Jump to content

Bitcoin: Difference between revisions

Edit links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
→Legal status and regulation: Restored previous citations. The Slate citation seems like an editorial; the Register and Reuters are news articles. Also, no need to put multiple cites per ref tag; multiple ref tags are normal in Wikipedia.
Line 122: Line 122:


==Criminal activity==
==Criminal activity==
Bitcoins have become linked to online criminal behavior and so-called [[cybercriminal]]s. Used to obfuscate online transactions, bitcoins are seized when [[Deep Web|dark web]] black markets are shut by authorities.<ref>For obfuscation of transactions and seizure of bitcoins from black market Utopia, see {{cite web | url=http://www.bbc.co.uk/news/technology-26158012 | title=Five arrested in Utopia dark net marketplace crackdown | publisher=BBC | work=bbc.co.uk | date=12 February 2014 | accessdate=13 February 2014 | author=Kelion, Leo}}
Bitcoins have become linked to online criminal behavior and so-called [[cybercriminal]]s.<ref>http://www.commdiginews.com/business-2/business-cyberhighway/brand-com-blackmail-cyber-attack-shines-light-on-cybercrime-11690/</ref> <ref>http://www.valuewalk.com/2014/03/mike-zammuto/</ref> <ref>http://segment.com/mike-zammuto-cyber-attack-brand-com/</ref> Used to obfuscate online transactions, bitcoins are seized when [[Deep Web|dark web]] black markets are shut by authorities.<ref>For obfuscation of transactions and seizure of bitcoins from black market Utopia, see {{cite web | url=http://www.bbc.co.uk/news/technology-26158012 | title=Five arrested in Utopia dark net marketplace crackdown | publisher=BBC | work=bbc.co.uk | date=12 February 2014 | accessdate=13 February 2014 | author=Kelion, Leo}}
*For seizure of bitcoins from black market Silk Road, see {{cite web|url=http://www.forbes.com/sites/andygreenberg/2013/10/25/fbi-says-its-seized-20-million-in-bitcoins-from-ross-ulbricht-alleged-owner-of-silk-road/ |title=FBI Says It's Seized $28.5 Million In Bitcoins From Ross Ulbricht, Alleged Owner Of Silk Road |publisher=Forbes |date= |accessdate=24 November 2013}}</ref> The association with criminal activities has stigmatized the currency and attracted the attention of financial regulators, legislative bodies, and law enforcement.<ref>For Bitcoin enthusiasts worries that the currency may be stigmatized as "drug barter tokens", see Chen, Adrian (1 June 2011). {{cite web |url=http://gawker.com/5805928/the-underground-website-where-you-can-buy-any-drug-imaginable |title=The Underground Website Where You Can Buy Any Drug Imaginable |deadurl=no}}. Gawker.
*For seizure of bitcoins from black market Silk Road, see {{cite web|url=http://www.forbes.com/sites/andygreenberg/2013/10/25/fbi-says-its-seized-20-million-in-bitcoins-from-ross-ulbricht-alleged-owner-of-silk-road/ |title=FBI Says It's Seized $28.5 Million In Bitcoins From Ross Ulbricht, Alleged Owner Of Silk Road |publisher=Forbes |date= |accessdate=24 November 2013}}</ref> The association with criminal activities has stigmatized the currency and attracted the attention of financial regulators, legislative bodies, and law enforcement.<ref>For Bitcoin enthusiasts worries that the currency may be stigmatized as "drug barter tokens", see Chen, Adrian (1 June 2011). {{cite web |url=http://gawker.com/5805928/the-underground-website-where-you-can-buy-any-drug-imaginable |title=The Underground Website Where You Can Buy Any Drug Imaginable |deadurl=no}}. Gawker.
*For attention by law enforcement and regulatory bodies, see {{cite web|url=http://www.bloomberg.com/news/2013-08-08/did-the-sec-just-validate-bitcoin-no-.html|title=The SEC Shows Why Bitcoin Is Doomed|publisher=Bloomberg LP|work=bloomberg.com | date=8 August 2013|accessdate=20 October 2013|author=Lavin, Tim}}</ref> CNN has referred to bitcoin as a "shady online currency [that is] starting to gain legitimacy in certain parts of the world,"<ref name="cnn">{{cite web|url=http://finance.fortune.cnn.com/2012/12/18/bitcoin-money-laundering/|title=Bitcoin looks primed for money laundering|publisher=CNN | work=money.cnn.com | date=18 December 2012|accessdate=18 October 2013 | author=Sanati, Cyrus}}</ref> and the Washington Post calls it "the currency of choice for seedy online activities."<ref name="washp">{{cite web | url=http://articles.washingtonpost.com/2013-10-02/business/42613812_1_digital-currency-federal-authorities-reputation | title=Authorities shut down Silk Road, the world's largest Bitcoin-based drug market|work=The Washington Post|date=2 October 2013|accessdate=21 October 2013 | author=Timothy B. Lee and Hayley Tsukayama}}</ref> The FBI stated in a 2012 report that "bitcoin will likely continue to attract cyber-criminals who view it as a means to move or steal funds".<ref name="fbi_report">{{cite web | url=http://cryptome.org/2012/05/fbi-bitcoin.pdf | title=Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity | publisher=FBI | work=Cyber Intelligence Section and Criminal Intelligence Section | date=24 April 2012|accessdate=20 October 2013}}</ref>
*For attention by law enforcement and regulatory bodies, see {{cite web|url=http://www.bloomberg.com/news/2013-08-08/did-the-sec-just-validate-bitcoin-no-.html|title=The SEC Shows Why Bitcoin Is Doomed|publisher=Bloomberg LP|work=bloomberg.com | date=8 August 2013|accessdate=20 October 2013|author=Lavin, Tim}}</ref> CNN has referred to bitcoin as a "shady online currency [that is] starting to gain legitimacy in certain parts of the world,"<ref name="cnn">{{cite web|url=http://finance.fortune.cnn.com/2012/12/18/bitcoin-money-laundering/|title=Bitcoin looks primed for money laundering|publisher=CNN | work=money.cnn.com | date=18 December 2012|accessdate=18 October 2013 | author=Sanati, Cyrus}}</ref> and the Washington Post calls it "the currency of choice for seedy online activities."<ref name="washp">{{cite web | url=http://articles.washingtonpost.com/2013-10-02/business/42613812_1_digital-currency-federal-authorities-reputation | title=Authorities shut down Silk Road, the world's largest Bitcoin-based drug market|work=The Washington Post|date=2 October 2013|accessdate=21 October 2013 | author=Timothy B. Lee and Hayley Tsukayama}}</ref> The FBI stated in a 2012 report that "bitcoin will likely continue to attract cyber-criminals who view it as a means to move or steal funds".<ref name="fbi_report">{{cite web | url=http://cryptome.org/2012/05/fbi-bitcoin.pdf | title=Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity | publisher=FBI | work=Cyber Intelligence Section and Criminal Intelligence Section | date=24 April 2012|accessdate=20 October 2013}}</ref>

Revision as of 20:54, 11 March 2014

Bitcoin
A common logo from the Bitcoin reference client
Unit
Symbol BTC, XBT,[1] , ฿[2][note 1]‎
Denominations
Subunit
 10−8satoshi[3]
Demographics
Date of introduction3 January 2009; 15 years ago (2009-01-03)
User(s)Worldwide
Valuation
Money Supply25 bitcoins per block (approximately every ten minutes)[4]
 SourceNumber of bitcoins in circulation
This article contains special characters. Without proper rendering support, you may see question marks, boxes, or other symbols.

Bitcoin is a peer-to-peer payment system and digital currency introduced as open source software in 2009 by developer Satoshi Nakamoto. It is a cryptocurrency, so-called because it uses cryptography to control the creation and transfer of money.[5] Conventionally, the capitalized word "Bitcoin" refers to the technology and network, whereas lowercase "bitcoin" refers to the currency itself.[6]

Bitcoins are created by a process called mining, in which participants verify and record payments into a public ledger in exchange for transaction fees and newly minted bitcoins.[7] Users send and receive bitcoins using wallet software on a personal computer, mobile device, or a web application. Bitcoins can be obtained by mining or in exchange for products, services, or other currencies.[8]

Bitcoin has been a subject of scrutiny amid concerns that it can be used for illegal activities.[9][10] In 2013 the U.S. FBI shut down the Silk Road online black market and seized 144,000 bitcoins worth US$28.5 million at the time.[11] The U.S. is considered Bitcoin-friendly compared to other governments, however.[12] In China new rules restrict bitcoin exchange for local currency.[13] The European Banking Authority has warned that Bitcoin lacks consumer protections.[14] Bitcoins can be stolen and chargebacks are impossible.[15]

Commercial use of Bitcoin, illicit or otherwise, is currently small compared to its use by speculators, which has fueled price volatility.[16] Bitcoin as a form of payment for products and services has seen growth, however, and merchants have an incentive to accept the currency because transaction fees are lower than the 2–3% typically imposed by credit card processors.[17]

Transactions

Further information: Bitcoin network

Users send payments by broadcasting digitally signed messages to the network requesting an update to the public transaction database, the block chain. A transaction transfers ownership from one Bitcoin address to another Bitcoin address and must be recorded in the block chain to take effect. Approximately every ten minutes a bundle of transactions, called a "block", is added to a public ledger or transaction record called the block chain. The incentive for this accounting process, known as "mining", carries a reward of 25 bitcoins per block added to the block chain.[18] This 25 bitcoins reward maintains the integrity of the Bitcoin system by allowing the computers that confirm transactions to also mint new bitcoins in the process. Bitcoin payment processing fees are optional and generally substantially lower than those of credit cards or money transfers.[19]

Buying and selling bitcoins

Bitcoin can be bought and sold for many different currencies from individuals and from companies. The fastest way to obtain bitcoins is to purchase them in person for cash.[20] Participants in online exchanges offer bitcoin buy and sell bids.[21] Companies buy or sell bitcoin in bulk on exchanges and offer their customers the option via ATM to buy or sell bitcoin at market price.[22] Bitcoin ATMs allow cash-for-bitcoins transactions to be made.[23] Using an online exchange to obtain bitcoins entails some risk, since according to one study 45% of exchanges have failed and taken client bitcoins with them.[24] Since bitcoin transactions are irreversible, sellers of bitcoins must take extra measures to ensure they have received traditional funds from the buyer.

Block chain

Integral to Bitcoin is a public ledger, a database with a sequential record of all transactions, known as the block chain, that records bitcoin ownership at present and at all points in the past. By keeping a record of all transactions, the block chain prevents double-spending, a problem particular to digital money.[18] The block chain provides only a certain level of anonymity; it identifies receivers by Bitcoin addresses, not individuals' names. Tracking the flow of bitcoins can give clues as to who owns them.[25] Bitcoin intermediaries, such as exchanges, are required by law in many jurisdictions to collect personal customer data.[26]

Mining

Those who maintain the block chain are called miners and are rewarded with newly created bitcoins as well as transaction fees. Payment processing work done by miners verifies each transaction as valid and adds it to the block chain.[27] As of 2014 payment processing is rewarded with 25 newly created bitcoins per block. To claim the reward, the miner includes in the block a special transaction called the "coinbase" that assigns the reward bitcoins to an address of the miner's choosing. All bitcoins in circulation can be traced back to such coinbase transactions. The block reward will be halved to 12.5 bitcoins in 2017 and again approximately every four years thereafter. By 2014 estimates there will be 21 million bitcoins in existence in 2140, and transaction processing will only be rewarded by the transaction fees.[28] Transactions that pay a fee may be processed more quickly than those that don't.[citation needed] The most efficient mining hardware makes use of custom designed application-specific integrated circuits, which are much faster mining and have low power consumption compared to general purpose microprocessors, such as x86 processors.[29]

Wallets

File:Bitcoin-coins.jpg
Example of Casascius physical bitcoins[30]
A paper wallet with QR codes

Bitcoin uses public-key cryptography, in which a pair of a public and a private cryptographic key is generated.[31] A collection of keys is called a wallet. Note that sometimes the term is used to mean the software in the sense of digital wallet. A Bitcoin transaction transfers ownership to a new address, a string having the form of random letters and numbers derived from public keys by application of a hash function and encoding scheme. The corresponding private keys act as a safeguard for the owner; a valid payment message from an address must contain the associated public key and a digital signature proving possession of the associated private key. Because anyone with a private key can spend all of the bitcoins sent to the corresponding address, the essence of Bitcoin security is protection of private keys. Theft of bitcoins has occurred on numerous occasions,[32] and the practical day-to-day security of Bitcoin wallets is a concern like the security of other forms of payment.[33] Risk of theft can be reduced by generating keys offline on an uncompromised computer and saving them on external storage or paper printouts.[34] The ubiquitous media images of "physical bitcoins", produced by various vendors confuse and do not do justice to their function; they store a private key on paper, metal,[35] wood,[36] or plastic. There are also digital products known as "Hardware Wallets" to store bitcoins securely on a physical device.[37]

Software

Electrum – sample Bitcoin client

Bitcoin wallet software, sometimes called a Bitcoin client, allows a user to transact bitcoins. A wallet program generates and stores private keys, and communicates with peers on the Bitcoin network. The first wallet program called Bitcoin-Qt was released in 2009 by Satoshi Nakamoto as open source code.[38] It can be used as a desktop wallet for payments or as a server utility for merchants and other payment services. Bitcoin-Qt, the so-called "Satoshi client" is sometimes also referred to as the reference client because it serves to define the Bitcoin protocol and acts as a standard for other implementations.[38] When making a purchase with a mobile device, QR codes are used ubiquitously to simplify transactions. Several server software implementations of the Bitcoin protocol exist. So-called "full" nodes on the network validate transactions and blocks they receive, and relay them to connected peers.[38]

History

Main article: History of Bitcoin

Bitcoin was first mentioned in a 2008 paper published under the name Satoshi Nakamoto. In early 2009, the first open source client (or wallet software), called Bitcoin-Qt, was released and the first bitcoins were issued. In 2009, a feature in the Bitcoin-Qt software was exploited and large amounts of bitcoins were created.[39] This was due, in large part, because Bitcoin-Qt was the only software that facilitated bitcoin transactions and mining. This feature was later removed because specialized mining software turned out to be more efficient.[38] Since then, the bitcoin open-source software has been maintained and enhanced by a group of core developers and other contributors.

By May 2011, interest in Bitcoin was growing as were concerns. Jason Calacanis stated in a report "Bitcoin may be the most dangerous technological project since the internet itself".[40] The price of bitcoins has fluctuated wildly since its inception, going through various cycles of appreciation and depreciation, which have been referred to by some as bubbles and busts.[41] In 2011, the value of one bitcoin rapidly rose from about US$0.30 to US$32 before returning to US$2.[42] In the latter half of 2012 and during the 2012-2013 Cypriot Financial Crisis, the bitcoin price[43] began to rise, reaching a peak of US$266 on April 10, 2013, before crashing to around US$50.[44]

In March 2013, a technical glitch caused a fork in the block chain, with one half of the network adding blocks to one version of the chain and the other half adding to another. For six hours two Bitcoin networks operated at the same time, each with its own version of the transaction history. The core developers called for a temporary halt to transactions, sparking a sharp sell-off. Normality was restored only when the majority of the network downgraded to version 0.7 of the Bitcoin software from the flawed version 0.8.[39]

Mainstream services began accepting bitcoins as a form of payment[45] as well as certain non-profit or advocacy groups such as the Electronic Frontier Foundation.[46] The first law enforcement events occurred in May 2013: Assets belonging to the Mt. Gox exchange were seized by Department of Homeland Security[47] and the Silk Road drug market website was shut down by the FBI.[48]

In October 2013, Chinese internet giant Baidu had allowed clients of website security services to pay with bitcoins.[49] During November 2013, the China-based bitcoin exchange BTC China overtook the Japan-based Mt. Gox and the Europe-based Bitstamp to become the largest bitcoin trading exchange by trade volume.[50] On 19 November 2013, the value of a bitcoin on the Mt. Gox exchange soared to a peak of US$900 after a United States Senate committee hearing was told that virtual currencies were a legitimate financial service.[51] On the same day, one bitcoin traded for over RMB¥6780 (US$1100) in China.[52] On December 5, 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins.[13] After the announcement, the value of bitcoins dropped[53] and Baidu no longer accepted bitcoins for certain services.[54] Buying real-world goods with any virtual currency had been illegal in China since at least 2009.[55]

With roughly 12 million existing bitcoins as of November 2013,[56] the new price increased the market cap for Bitcoin to at least US$7.2 billion.[57] By November 23, 2013, the total market capitalization of Bitcoin exceeded US$10 billion for the first time.[58]

Since US bitcoin exchanges are regulated as money services businesses, they are obligated to report activity suspicious of money laundering.[citation needed] Two men were arrested in January 2014 on charges of money-laundering using bitcoins: Charlie Shrem, the head of defunct bitcoin exchange BitInstant and vice chairman of the Bitcoin Foundation, and Robert Faiella. Shrem allegedly allowed Faiella to purchase large quantities of bitcoins and to use them to buy illegal drugs on black-market websites.[59]

In early February 2014, the Mt. Gox exchange suspended withdrawals, citing technical issues related to "transaction malleability".[60] While the company worked on a fix, one week later the price of a bitcoin had come down from over US$800 on February 1 to US$400.[61] On February 24, 2014, Mt. Gox's website was taken offline and all trading stopped, amid reports that $350 million worth of bitcoins had been stolen over several years because of flaws in its payment software.[62]

On February 18, 2014, Vegas-based Robocoin announced it was installing the first bitcoin automated teller machines in the United States in Seattle, WA and Austin, TX.[63]

Economics

Bitcoin has garnered comments and attention from economists and journalists, as well as investors and speculators. Others who mistrust their national currency have seen bitcoin as a safe haven from inflation and a way to circumvent capital controls.[64] The bitcoin market currently suffers from volatility, limiting bitcoin utility to act as a currency. This has not prevented their being used as a medium of exchange.[65] Bitcoin is used as a currency,[66] with about 1,000 brick and mortar businesses willing to accept payment in bitcoins as of November 2013[67] and more than 35,000 merchants online.[68] Bitcoin has also become a target for speculators trading bitcoins as a speculative asset, an investment vehicle, and a network serving customers of international remittance business.

Price volatility

According to Mark T. Williams of Boston University, bitcoin is over 7 times as volatile as gold and over 8 times as volatile as the S&P 500.[69] The extremely volatile bitcoin exchange rate has led people to question its ability to function as a currency.[65] The Bitcoin Foundation contends that this is due to insufficient liquidity and claims volatility will lessen if its popularity continues to increase.[70] Volatility has little effect on the utility of Bitcoin as a payment processing system.[71] Volatility has damaged the ability of bitcoin to be a store of value; it has not hampered its function as a medium of exchange. Bitcoin volatility is linked to uncertainty about its long-term value per Forbes contributor Timothy B. Lee.[72]

Alternative to national currencies

Bitcoins are accepted in this café in the Netherlands as of 2013

Bitcoin detractors and supporters have suggested that Bitcoin is gaining popularity in countries with problem-plagued national currencies because it can be used to circumvent inflation, capital controls, and international sanctions. For example, bitcoins are used by some Argentinians as an alternative to the official currency,[73] stymied by inflation and strict capital controls.[26] In addition, some Iranians use bitcoins to evade currency sanctions.[74] A link between higher Bitcoin usage in Spain and the 2012–2013 Cypriot financial crisis has been suggested.[75] Mistrust in traditional financial institutions and central banks fostered by the financial crisis of 2007–08 has probably helped to bolster Bitcoin popularity.[citation needed]

Speculation and bubbles

Bitcoins are traded by speculators who want to profit on short to medium term price changes.[76] A separate organization offers futures contracts against multiple currencies allowing speculators to short bitcoin.[77] The European Banking Authority warned in December 2013, that the risks of engaging in speculation go beyond a potential loss of bitcoin value.[78] Because of bitcoin's volatile value former Federal Reserve Chairman Alan Greenspan has called it a speculative bubble[79] as has economist John Quiggin.[80] Two lead software developers of Bitcoin, Gavin Andresen[81] and Mike Hearn, had warned that bubbles may occur[82] One financial journalist correctly predicted the bursting of one such bitcoin bubble in April 2013.[83] Nobel Laureate Robert Shiller said that bitcoin "exhibited many of the characteristics of a speculative bubble."[84] Others reject the existence of bubbles and see bitcoin's quick rise in price as nothing more than normal economic forces at work.[85]

Bitcoin as investment

One way of investing into Bitcoin is to buy bitcoins to hold them as a long-term high-risk investment.[86] Winklevoss twins made a US$1.5 million personal investment[87] and attempt to launch a bitcoin ETF.[16] The New York Times has called vulnerability to hacking and theft to limit bitcoin use as an investment, especially for unsophisticated investors.[88] Other investors, like Peter Thiel's Founders Fund, which invested US$3 million, invest into Bitcoin infrastructure funding companies providing bitcoin payment services to merchants, bitcoin exchanges, bitcoin wallet services, etc.[87] Investors also invest into bitcoin mining.[89]

Money supply

Growth of the Bitcoin money supply is predefined by the Bitcoin protocol,[28] and in this way inflation is kept in check. Currently there are over twelve million bitcoins in circulation with an approximate creation rate of 25 bitcoins every ten minutes. The total supply is capped at 21 million,[28] and every four years the creation rate is halved. This means new bitcoins will continue to be released for more than a hundred years.

Bitcoin value forecasts

Financial journalists and analysts, economists, and investors have attempted to predict the possible future value of bitcoin. Economist John Quiggin stated, "bitcoins will attain their true value of zero sooner or later, but it is impossible to say when."[80] In 2013, Bank of America FX and Rate Strategist David Woo forecast a maximum fair value per bitcoin of $1,300.[90] Bitcoin investor Cameron Winklevoss stated in 2013 that the "bull case scenario for bitcoin is... 40,000 USD a coin".[91] In late 2013, finance professor Mark Williams forecast a bitcoin would be worth less than ten US dollars by July 2014.[92]

Reception

Some economists have responded positively to Bitcoin, including François R. Velde, a senior economist at the Federal Reserve in Chicago, who described it as "an elegant solution to the problem of creating a digital currency."[93] Economists Paul Krugman and Brad DeLong have found fault with Bitcoin in that bitcoins are not a reliable store of value and that there is no floor on their value.[94] Economist John Quiggin has criticised Bitcoin as "the final refutation of the efficient-market hypothesis".[80] Free software movement activists including Richard Stallman have criticized the lack of anonymity and called for reformed development.[95] PayPal President David A. Marcus calls bitcoin a "great place to put assets" but claims it will not be a currency until price volatility is reduced.[96] One Magistrate Judge of Texas federal court has classified bitcoin as currency.[97] A German court found bitcoin to be a unit of account. The Finnish Government judged it to be a commodity in January 2014[98] as did a WSJ journalist in December 2013[99] A Forbes journalist referred to bitcoins as "digital collectible".[100]

Acceptance by merchants

Large, established firms that accept bitcoins include Overstock.com,[101] the Sacramento Kings,[102] TigerDirect,[103] Clearly Canadian,[104] and Zynga.[105] In November 2013, Richard Branson announced that Virgin Galactic would accept bitcoin as a method of payment.[106] In November 2013, the University of Nicosia became the first accredited university in the world to accept it as a method of payment for tuition and fees.[107]

While some governments have taken a hands-off approach, others have moved to regulate bitcoin and similar private currencies. Steven Strauss, a Harvard public policy professor, suggested governments could outlaw Bitcoin,[108] a possibility that was mentioned in a 2013 SEC filing made by a Bitcoin investment vehicle.[109]

Critics have accused Bitcoin of being a Ponzi scheme,[110][111] though Bitcoin supporters disagree.[112] A 2012 case study report by the European Central Bank noted that Bitcoin shares some, but not all, characteristics of Ponzi schemes and concluded that "it [is not] easy to assess whether or not the Bitcoin system actually works like a pyramid or Ponzi scheme."[113]

Regulation

Main article: Legal status of Bitcoin

Because Bitcoin does not involve traditional financial actors, and both issuers of bitcoins and software/hardware owners are non-financial private companies, traditional financial sector regulation is not applicable.[114] In the US the first step of regulation occurred in July 2011, when the Department of Treasury added “other value that substitutes for currency” to its definition of Money services businesses.[115] In 2013 the Treasury issued an interpretive guidance regarding virtual currencies,[116] according to which, exchangers and administrators, but not users of convertible virtual currency are considered money transmitters, and must comply with rules to prevent money laundering/terrorist financing ("AML/CFT") and other forms of financial crime.[117] There are no rules at the state level as of 3/2014. The U.S. Government Accountability Office reviewed virtual currencies upon request of the Senate Finance Committee and recommended [118] that the Internal Revenue Service formulate a tax guidance for bitcoin business.

The 2013 G7's Financial Action Task Force(FATF) guidance for internet-based payment services[119] defines "exchangers buying or selling digital currency for cash (or other digital currencies) [...] as a virtual bureau de change"(p10) and warns "internet-based payment services that allow third party funding from anonymous sources may face an increased risk of ML/TF [money laundering/terrorist financing]"(p16) and that "such exchangers can circumvent an Internet-based payment service provider’s ban on certain funding methods (e.g. a ‘no cash funding’ policy) if they accept the banned payment methods when reselling the issued digital currency..." so "the provider will only see the exchanger´s name in its monitoring, but will not see who actually instructed the exchanger to fund the account"(p16) and this may "pose challenges to countries in AML/CFT regulation and supervision because their cross-border functionality"(p31), wherefore as a minimum countries "should be licensed or registered and subject to effective monitoring systems...."(p34)

In Canada, the federal government announced that it was going to regulate Bitcoin under its anti-money laundering and counter-terrorist financing legislation, the Proceeds of Crime (Money Laundering) and Terrorist Financing Act. [120]The Quebec government agency, the Autorité des marches financiers, also announced that it would prosecute violations of the Securities Act (Loi sur les valeurs mobilières), the Derivatives Act (Loi sur les instruments dérivés) and the Money Services Businesses Act (Loi sur les enterprises de services monétaires) for Bitcoin transactions, particularly those involving Bitcoin ATMs. [121]

Criminal activity

Bitcoins have become linked to online criminal behavior and so-called cybercriminals.[122] [123] [124] Used to obfuscate online transactions, bitcoins are seized when dark web black markets are shut by authorities.[125] The association with criminal activities has stigmatized the currency and attracted the attention of financial regulators, legislative bodies, and law enforcement.[126] CNN has referred to bitcoin as a "shady online currency [that is] starting to gain legitimacy in certain parts of the world,"[127] and the Washington Post calls it "the currency of choice for seedy online activities."[128] The FBI stated in a 2012 report that "bitcoin will likely continue to attract cyber-criminals who view it as a means to move or steal funds".[129]

Criminal activity involving Bitcoin has largely centered around theft of the currency, money laundering, the use of botnets for mining, and the use of bitcoins in exchange for illegal items or services. Certain nation states may feel that its use in circumventing capital controls is also undesirable.[12] Despite claims made by the non-profit Bitcoin Foundation that "cryptography is the reason no one can steal bitcoins," theft is widespread.[130]

Black markets

Several news outlets assert that the popularity of bitcoin hinges on the ability to use them to purchase illegal goods.[131] C. 2013 Non-drug transactions were thought to be far less than the number involved in the purchase of drugs,[132] and roughly one half of all transactions made using Bitcoin were bets placed at a single online gaming website.[133] Some also state that online gun dealers use Bitcoin to sell arms without background checks.[134] In 2012, an academic from the Carnegie Mellon CyLab and the Information Networking Institute estimated that 4.5 to 9% of all bitcoins transacted were for purchases of drugs at a single online market, Silk Road.[135] As the majority of the Bitcoin transactions were then speculative, the academic asserts that drugs constituted a much larger percentage of the purchases with the currency.[135] Silk Road was later shut by US law enforcement. Some feel dark web black markets are operated in order to steal bitcoins from shoppers. The Bitcoin community branded one site, Sheep Marketplace, as a scam when it prevented withdrawals and shut down after an alleged bitcoins theft.[136] In a separate case, escrow accounts with bitcoins belonging to patrons of a different black market were hacked in early 2014.[137]

Money laundering

While some feel bitcoins are not ideal for money laundering because all transactions are public,[138] authorities have expressed concerns. The European Banking Authority and the FBI have both stated that Bitcoin may be used for money laundering.[139] In early 2014, an operator of a US bitcoin exchange was arrested for money laundering.[59]

Ponzi scheme

In an alleged Ponzi scheme that utilized bitcoins, The Bitcoin Savings and Trust allegedly promised investors up to 7 percent weekly interest, and raised at least 700,000 bitcoins from 2011 to 2012.[140][141] In 2013, the SEC charged the company and its founder "with defrauding investors in a Ponzi scheme involving Bitcoin..."[141]

Thefts and loss

While generating and storing keys offline mitigates theft of bitcoins, thefts occur on a regular basis.[22] Theft occurs when an unauthorized transfer of bitcoins is made from a wallet using the private key to unlock the wallet.[142] Most large-scale thefts occur at payment processors, exchanges, or online wallet services that store the private keys of many bitcoin users: The thief hacks an online wallet service by finding a bug in its website or spreading malware to computers holding the private keys.[143][144] When they have control of the website or its database, they gain access to many users' private keys and can thereby steal those users' bitcoins.

Many high-profile bitcoin thefts have been reported: In late November 2013, an estimated 96,000 bitcoins, then valued at around $100 million, were stolen from the online illicit goods marketplace Sheep Marketplace, which immediately closed.[145][146] Users tracked the coins as they were processed by the bitcoin exchange BTC-e, where they were apparently converted to cash, but no funds were recovered or culprits identified.[146] A black market called Silk Road 2, stated that during a February 2014 hack bitcoins valued at $2.7 million were taken from escrow accounts.[137] On February 28, 2014 Mt. Gox, one of the world's biggest virtual currency exchanges filed for bankruptcy in Tokyo after its computer system was hacked and lost 850,000 bitcoins (750,000 of customer bitcoins and 100,000 of Mt. Gox own bitcoins) worth approximately $477 million at the time, representing around 7 percent of the world's supply.[147] Flexcoin, an Alberta, Canada-based bitcoin storage specialist, shut down on March 3, 2014 after it said it discovered the theft of 896 bitcoins, worth roughly $650,000.[148] The theft exploited a software flaw handling multiple, rapid inter-account transfers.[148] The company differentiated itself by incentivizing users to store bitcoins on their website.[149] Only bitcoins stored in hot wallets (i.e., connected to the internet) were stolen, and the company said it would return customer bitcoins kept offline in cold storage, an optional service that was available for a 0.5% fee.[149] Poloniex, a digital currency exchange, reported on March 4, 2014 that it lost 76.69 bitcoins to hackers, or 12.3% of its bitcoin holdings, valued at around $50,000.[150] Multiple withdrawals were placed at nearly the same time in the attack, and the exchange did not adequately guard against negative balances.[150] Poloniex said it would reduce customer account balances by 12.3%, and repay the deductions in the future.[150]

Besides being stolen, bitcoins can be lost. In 2013 one user claimed to have lost 7,500 bitcoins, worth £4.0m at the time, when he inadvertently discarded a hard drive containing his private keys. Some are sceptical of this claim.[151]

Malware

Bitcoin-related malware includes software that steals bitcoins from users using a variety of techniques, software that uses infected computers to mine bitcoins, and different types of ransomware which disable computers until ransom is paid, such as Cryptolocker.

Unauthorized mining

In June 2011, Symantec warned about the possibility that botnets could mine covertly for bitcoins.[152] Malware used the parallel processing capabilities of GPUs built into many modern video cards.[153] In mid-August 2011, bitcoin mining botnets were detected again,[154] and less than three months later, bitcoin mining trojans had infected Mac OS X.[155] In April 2013, electronic sports organization E-Sports Entertainment was accused of hijacking 14,000 computers to mine bitcoins; the case was settled in November with a fine of $325,000 increasing to US$1 million if the organization were to break the law within the following ten years.[156] While bitcoin mining on an average PC is no longer lucrative, botnet networks of tens of thousands of infected computers can mine for bitcoins without concern for power costs.[157] German police arrested two people in December 2013 who customized existing botnet software to perform bitcoin mining, which police said had been used to mine at least $950,000 worth of bitcoins.[158][159] For four days in December 2013 and January 2014, Yahoo's European servers served an ad that contained Windows bitcoin mining malware which infected an estimated 2 million PCs.[157] Bitcoin-mining botnet software called Sefnit, first detected in mid-2013, was bundled with many software packages; Microsoft has been removing the malware through its Microsoft Security Essentials and other security software since January 2014.[160]

Malware stealing bitcoins

Security company Dell SecureWorks said in February 2014 that they had identified 146 strains of bitcoin malware in circulation, almost all of it targeting Windows users, and about half of the malware undetected by standard antivirus scanners.[161] The most common type searches computers for cryptocurrency wallets to upload to a remote server, where they can be cracked and their coins stolen.[161] Many of these also log keystrokes to record passwords, often avoiding the need to crack the keys.[161] A different approach taken by some malware is to detect when Bitcoin addresses are copied to a clipboard, and replace it with a different address, tricking people into sending bitcoins to the wrong address.[161]

One virus, spread through the Pony botnet, was reported in February 2014 to have stolen up to $220,000 in cryptocurrencies, including 335 bitcoins, from 85 wallets.[149] Security company Trustwave tracked the malware since September 2013, reporting that it had also stolen millions of passwords to various websites, and that its latest version was able to steal from 30 types of digital currency wallets.[149][162]

A trojan horse for Mac OS X, called CoinThief, hidden in versions of some cryptocurrency apps on Download.com and MacUpdate, was reported in February 2014 to be responsible for multiple bitcoin thefts, including one user who lost 20 bitcoins.[163] It bore similarities to a piece of Mac malware active in August 2013, Bitvanity, which posed as a vanity wallet address generator, and stole addresses and private keys from other Bitcoin client software.[163]

Ransomware

Another type of Bitcoin-related malware is a type of ransomware. A program called Cryptolocker, typically spread through legitimate-looking email attachments, encrypts the hard drive of an infected computer, then displays a countdown timer and demands a ransom, usually two bitcoins, to decrypt it.[164] Police in Massachusetts said they paid a 2 bitcoin ransom in November 2013, worth more than $1300 at the time, to decrypt one of their hard drives.[165] Linkup, a combination ransomware and bitcoin mining program that surfaced in February 2014, disables a user's internet access and demands credit card information to restore it, while secretly mining bitcoins.[164] Researchers at Emsisoft did not test whether entering the information really restored internet access.[164]

See also

Notes

  1. ^ This also is the baht symbol

References

  1. ^ Jon Matonis (17 September 2013). "Bitcoin gaining market-based legitimacy as XBT". Coindesk. Retrieved 14 December 2013.
  2. ^ Matonis, Jon (22 January 2013). "Bitcoin Casinos Release 2012 Earnings". Forbes. New York. Archived from the original on 16 February 2013. Responsible for more than 50% of daily network volume on the Bitcoin blockchain, SatoshiDice reported first year earnings from wagering at an impressive ฿33,310. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  3. ^ "Cracking the Bitcoin: Digging Into a $131M USD Virtual Currency". Daily Tech. 12 June 2011. Archived from the original on 20 January 2013. Retrieved 30 September 2012. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  4. ^ Ron Dorit; Adi Shamir (2012). "Quantitative Analysis of the Full Bitcoin Transaction Graph" (PDF). Cryptology ePrint Archive. Retrieved 18 October 2012.
  5. ^ Steadman, Ian (11 May 2013). "Wary of Bitcoin? A guide to some other cryptocurrencies". Ars Technica. Retrieved 10 January 2014.
  6. ^ Bustillos, Maria (2 April 2013). "The Bitcoin Boom". The New Yorker. Condé Nast. Retrieved 22 December 2013. ...there seems to be a consensus forming around Bitcoin, capitalized, for the system, the software, and the network it runs on, and bitcoin, lowercase, for the currency itself
  7. ^ Jerry Brito and Andrea Castillo (2013). "Bitcoin: A Primer for Policymakers" (PDF). Mercatus Center. George Mason University. p. 5. Retrieved 22 October 2013.
  8. ^ "How do I get Bitcoins? (For Beginners)". The Bitcoin Bulletin. 11 March 2011. Retrieved 13 December 2013.
  9. ^ Tracy, Ryan (5 November 2013). "Bitcoin Comes Under Senate Scrutiny". The Wall Street Journal.
  10. ^ Ostroukh, Andrey (10 February 2014). "Russia to crack down on virtual currencies". The Wall Street Journal.
  11. ^ "FBI Says It's Seized $28.5 Million In Bitcoins From Ross Ulbricht, Alleged Owner Of Silk Road". Forbes. Retrieved 24 November 2013.
  12. ^ a b Peterson, Andrea (27 January 2014). "This map shows which countries are friendly to Bitcoin". The Switch. The Washington Post. Retrieved 28 January 2014. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
  13. ^ a b Kelion, Leo (18 December 2013). "Bitcoin sinks after China restricts yuan exchanges". bbc.com. BBC. Retrieved 20 December 2013.
  14. ^ Smith, Geoffery (12 December 2013). "European Banking Watchdog Warns on Bitcoin". WSJ.com. Dow Jones. Retrieved 20 December 2013.
  15. ^ For theft, see Nathaniel Popper (5 December 2013). "In the Murky World of Bitcoin, Fraud Is Quicker Than the Law". The New York Times. Retrieved 12 December 2013. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
    • For lack of chargebacks, see Jerry Brito and Andrea Castillo (2013). "Bitcoin: A Primer for Policymakers" (PDF). Mercatus Center. George Mason University. p. 12. Retrieved 22 October 2013.
  16. ^ a b Grocer, Stephen (2 July 2013). "Beware the Risks of the Bitcoin: Winklevii Outline the Downside". Moneybeat. The Wall Street Journal. Retrieved 21 October 2013. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
  17. ^ For growth in merchant numbers, see "BitPay Passes 10,000 Bitcoin-Accepting Merchants On Its Payment Processing Network". Techcrunch. Techcrunch.com. 16 September 2013. Retrieved 21 October 2013.
  18. ^ a b Wallace, Benjamin (23 November 2011). "The Rise and Fall of Bitcoin". Wired. Retrieved 4 November 2013.
  19. ^ Wingfield, Nick (30 October 2013). "Bitcoin Pursues the Mainstream". The New York Times. Retrieved 4 November 2013.
  20. ^ Lauren Orsini (23 October 2013). "Here's What Happened When I Bought Bitcoin In Person". Business Insider. Retrieved 4 February 2014.
  21. ^ "Bitcoin Markets (mtgoxUSD) - Bitcoin Charts". Quandl. Retrieved 20 November 2013.: 3 
  22. ^ a b Lee, Timothy B. (19 November 2013). "12 questions about Bitcoin you were too embarrassed to ask". The Washington Post. Retrieved 12 December 2013.
  23. ^ Gallivan, Joseph (12 January 2014). "First bitcoin ATM to debut in NYC". "New York Post". Retrieved 4 February 2014.
  24. ^ Steadman, Ian (26 April 2013). "Study: 45 percent of Bitcoin exchanges end up closing". Wired. Retrieved 28 April 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  25. ^ McMillan, Robert. "How Bitcoin lets you spy on careless companies". Retrieved 16 December 2013.
  26. ^ a b Lee, Timothy B. (19 August 2013). "Five surprising facts about Bitcoin". Washington Post blog. Archived from the original on 22 August 2013.
  27. ^ Ashlee Vance (14 November 2013). "2014 Outlook: Bitcoin Mining Chips, a High-Tech Arms Race". Businessweek. Retrieved 24 November 2013.
  28. ^ a b c Ritchie S. King Sam Williams David Yanofsky (17 December 2013). "By reading this article, you're mining bitcoins". qz.com. Atlantic Media Co. Retrieved 17 December 2013.
  29. ^ "MANIC MINERS: Ten Bitcoin generating machines". The Register. 20 January 2014. Retrieved 13 February 2014.
  30. ^ Bustillos, Maria. "The Future of Bitcoin". The New Yorker. Retrieved 3 December 2013. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
  31. ^ "Bitcoin: Bitcoin under pressure". The Economist. 30 November 2013. Retrieved 30 November 2013.
  32. ^ Moore, Tyler and Nicolas Christin (April 2013). "Beware the Middleman: Empirical Analysis of Bitcoin-Exchange Risk. In Proceedings of the 17th International Conference on Financial Cryptography and Data Security (FC'13)" (PDF). {{cite journal}}: Cite journal requires |journal= (help)
  33. ^ Rubens, Paul. "BBC News - Cybercrime shopping list study points to falling prices". Bbc.co.uk. Retrieved 17 December 2013.
  34. ^ Danny Bradbury (27 December 2013). "5 things to do with those Christmas bitcoins". Coindesk.com. Retrieved 14 January 2014.
  35. ^ Staff, Verge (13 December 2013). "Casascius, maker of shiny physical bitcoins, shut down by Treasury Department". The Verge. Retrieved 10 January 2014.
  36. ^ Daniel Cawrey (@danielcawrey) (20 December 2013). "Canadian Man Builds World's First Wooden Bitcoin Wallet". Coindesk.com. Retrieved 10 January 2014.
  37. ^ Joon Ian Wong (@joonian) (4 December 2013). "Trezor to Ship Physical Bitcoin Wallets in January". Coindesk.com. Retrieved 10 January 2014.
  38. ^ a b c d Skudnov, Rostislav (2012). Bitcoin Clients (PDF) (Bachelor's Thesis). Turku University of Applied Sciences. Retrieved 16 January 2014.
  39. ^ a b Buterin, Vitalik (12 March 2013). "Bitcoin Network Shaken by Blockchain Fork". Bitcoin Magazine. Retrieved 17 January 2014.
  40. ^ Sunday (15 May 2011). "L019: Bitcoin P2P Currency: The Most Dangerous Project We've Ever Seen - LAUNCH". Launch3.squarespace.com. Retrieved 7 January 2014.
  41. ^ "Bitcoin May Be Following This Classic Bubble Stages Chart". Forbes. 19 December 2013. Retrieved 7 January 2014.
  42. ^ Lee, Timothy (5 November 2013). "When will the people who called Bitcoin a bubble admit they were wrong". The Washington Post. Retrieved 10 January 2014.
  43. ^ Liu, Alec. "When Governments Take Your Money, Bitcoin Looks Really Good | Motherboard". Motherboard.vice.com. Retrieved 7 January 2014.
  44. ^ "An Illustrated History Of Bitcoin Crashes". Forbes. Retrieved 7 January 2014.
  45. ^ Van Sack, Jessica (27 May 2013). "Why Bitcoin makes cents". Boston Herald. Retrieved 15 August 2013.
  46. ^ Jeremy Kirk (19 May 2013). "Electronic Frontier Foundation again takes bitcoin donations". PCWorld. Retrieved 25 January 2014.
  47. ^ Dillet, Romain (16 May 2013). "Feds Seize Assets From Mt. Gox's Dwolla Account, Accuse It Of Violating Money Transfer Regulations". TechCrunch. Retrieved 15 May 2013.
  48. ^ Farrell, Greg (3 October 2013). "FBI Snags Silk Road Boss With Own Methods". Bloomberg. New York. Retrieved 27 October 2013.
  49. ^ Kapur, Saranya (OCT. 15, 2013). "China's Google Is Now Accepting Bitcoin". businessinsider.com. Business Insider, Inc. Retrieved 26 December 2013. {{cite web}}: Check date values in: |date= (help)
  50. ^ "As Chinese Investors Pile Into Bitcoin, China's Oldest Exchange, BTC China, Raises $5M From Lightspeed". TechCrunch. Retrieved 10 January 2014.
  51. ^ "BBC News - 'Legitimate' Bitcoin's value soars after Senate hearing". Bbc.co.uk. 19 November 2013. Retrieved 10 January 2014.
  52. ^ Lee, Cyrus (22 November 2013). "China no plans yet to legalize use of Bitcoins". ZDNet. Retrieved 27 November 2013.
  53. ^ "China bans banks from bitcoin transactions". The Sydney Morning Herald. 6 December 2013.
  54. ^ "Baidu Stops Accepting Bitcoins After China Ban". Bloomberg. New York. 7 December 2013. Retrieved 11 December 2013.
  55. ^ "China bars use of virtual money for trading in real goods". English.mofcom.gov.cn. 29 June 2009. Retrieved 10 January 2014.
  56. ^ Raskin, Max (18 November 2013). "U.S. Agencies to Say Bitcoins Offer Legitimate Benefits". Bloomberg. Retrieved 24 November 2013.
  57. ^ By Todd Wasserman2013-11-18 14:06:30 UTC (18 November 2013). "Bitcoin Tops $600, Up 60x Over the Last Year". Mashable.com. Retrieved 10 January 2014.{{cite web}}: CS1 maint: numeric names: authors list (link)
  58. ^ "Bitcoin Set to Boom in Latin America". Blog.panampost.com. 2 January 2014. Retrieved 7 January 2014.
  59. ^ a b Lee, Dave (27 January 2014). "US makes Bitcoin exchange arrests after Silk Road closure". bbc.co.uk. BBC. Retrieved 28 January 2014.
  60. ^ Biggs, John (10 February 2014). "What's Going On With Bitcoin Exchange Mt. Gox?". TechCrunch. Retrieved 26 February 2014.
  61. ^ Lee, Timothy B. "Bitcoin's largest exchange is dying. Here's why that's not a problem for Bitcoin". Washingtonpost.com. Retrieved 26 February 2014.
  62. ^ McMillan, Robert (24 February 2014). "Bitcoin Exchange Mt. Gox Goes Offline Amid Allegations of $350 Million Hack". Wired. Retrieved 24 February 2014.
  63. ^ Wahba, Phil (18 February 2014). "First U.S. bitcoin ATMs to open soon in Seattle, Austin". Reuters. Retrieved 26 February 2014.
  64. ^ John Delono (21 February 2014). "Bitcoin is a Safe Haven from Inflation". Bitcoin Reviewer. Retrieved 22 February 2014. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  65. ^ a b Moore, Heidi (3 April 2013). "Confused about Bitcoin? It's 'the Harlem Shake of currency'". The Guardian. London. Archived from the original on 29 April 2013. Retrieved 8 April 2013. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  66. ^ "Bitcoin: more than just the currency of digital vice". The Guardian. 4 March 2013. Archived from the original on 29 April 2013. Retrieved 20 April 2013. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  67. ^ Joon Ian Wong (28 November 2013). "CoinMap: Bitcoin-Accepting Merchants Increased 81% in November". CoinDesk. Retrieved 1 December 2013.
  68. ^ To obtain 35,000 figure, 16,000 merchants signed up with Bitcoin payment processor Coinbase are added to 20,000 merchants signed to BitPay.
  69. ^ http://cognoscenti.wbur.org/2013/12/05/bitcoin-currency-mark-t-williams
  70. ^ Wilkes, Tommy. "Backer defends virtual currency Bitcoin after big fall". Reuters. Retrieved 7 January 2014.
  71. ^ Roose, Kevin. "How Bitcoin Can Go Mainstream, in One Easy Step - Daily Intelligencer". Nymag.com. Retrieved 25 November 2013.
  72. ^ Lee, Timothy B. (4 November 2013). "Bitcoin Doesn't Have a Deflation Problem". Forbes. Retrieved 27 January 2014.
  73. ^ "Bitcoins gain traction in Argentina". Archived from the original on 29 April 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help).Blogs.ft.com (16 April 2013). Retrieved 20 April 2013.
  74. ^ Raskin, Max (29 November 2012). "Dollar-Less Iranians Discover Virtual Currency". BloombergBusinessWeek. Archived from the original on 17 April 2013. Retrieved 15 April 2013. {{cite journal}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  75. ^ Salyer, Kirsten (21 March 2013). "Fleeing the Euro for Bitcoins". Bloomberg L.P. Archived from the original on 10 April 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  76. ^ Gloria Goodale, Christian Science Monitor (17 September 2013). "The Rise Of Bitcoin: Is It A Solution Or Menace?". Business Insider. Retrieved 25 November 2013.
  77. ^ Foxman, Simone (2 April 2013). "How to short bitcoins (if you really must)". Quartz. Archived from the original on 29 April 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  78. ^ "Warning to consumers on virtual currencies" (PDF). European Banking Authority. 12 December 2013. Retrieved 23 December 2013.
  79. ^ Kearns, Jeff (4 December 2013). "Greenspan Says Bitcoin a Bubble Without Intrinsic Currency Value". bloomberg.com. Bloomberg LP. Retrieved 23 December 2013.
  80. ^ a b c Quiggin, John (16 April 2013). "The Bitcoin Bubble and a Bad Hypothesis". The National Interest. Archived from the original on 29 April 2013. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  81. ^ "Bitcoin's History of Crushing Speculators". The Motley Fool. 4 April 2013. Retrieved 7 January 2014.
  82. ^ Barford, Vanessa (13 December 2013). "Bitcoin: Price v hype". bbc.com. BBC. Retrieved 23 December 2013.
  83. ^ For Salmon's April 3rd prediction, see Salmon, Felix (3 April 2013). "The Bitcoin Bubble and the Future of Currency". medium.com. Retrieved 26 October 2013.
  84. ^ Shiller, Robert (1 March 2014). "In Search of a Stable Electronic Currency". New York Times. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  85. ^ Boesler, Matthew (7 March 2013). "ANALYST: The Rise Of Bitcoin Teaches A Tremendous Lesson About Global Economics". Business Insider. Archived from the original on 10 April 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  86. ^ Gustke, Constance (23 November 2011). "The Pros And Cons Of Biting on Bitcoins". CNBC. Archived from the original on 19 January 2013. Retrieved 4 December 2012. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  87. ^ a b Simonite, Tom (12 June 2013). "Bitcoin Millionaires Become Investing Angels". Computing News. Retrieved 13 June 2013.
  88. ^ Popper, Nathaniel (18 November 2013). "Regulators See Value in Bitcoin, and Investors Hasten to Agree". New York Times. Retrieved 27 November 2013.
  89. ^ "CoinSeed raises $7.5m, invests $5m in Bitcoin mining hardware – Investment Round Up". Red Herring. 24 January 2014. Retrieved 9 March 2014.
  90. ^ Sharf, Samantha (12 May 2013). "Bitcoin Gets Valued: Bank Of America Puts A Price Target On The Virtual Tender". Forbes. New York.
  91. ^ Schroeder, Stan (1 December 2013). "Cameron Winklevoss: Bitcoin Might Hit $40,000 Per Coin". Mashable. New York.
  92. ^ Williams, Mart (DEC. 17, 2013). "FINANCE PROFESSOR: Bitcoin Will Crash To $10 By Mid-2014". businessinsider.com. Business Insider. Retrieved 26 February 2014. {{cite web}}: Check date values in: |date= (help)
  93. ^ Cawrey, Daniel (7 November 2013). "Federal Reserve economist says bitcoin is a remarkable technical achievement". CoinDesk. Retrieved 24 November 2013.
  94. ^ Paul Krugman (28 December 2013). "Bitcoin Is Evil". krugman.blogs.nytimes.com. Retrieved 28 December 2013.
  95. ^ "Software activist calls for 'truly anonymous' Bitcoins to 'protect democracy'". Telegraph. Retrieved 27 December 2013.
  96. ^ Shankland, Stephen (10 December 2013). "PayPal president David Marcus: Bitcoin is good, NFC is bad". CNET. Retrieved 10 December 2013.
  97. ^ Coldewey, Devin (8 August 2013). "'Bitcoin is a currency': Federal judge says the virtual cash is real money". NBC News. Retrieved 27 January 2014.
  98. ^ "Bitcoin Judged Commodity in Finland After Failing Money Test". Bloomberg. New York. 20 January 2014. Retrieved 27 January 2014.
  99. ^ Chapman, Lizette (12 December 2013). "Coinbase to Push Bitcoin From Commodity to Currency, With $25M From Investors". The Wall Street Journal. Retrieved 27 January 2014.
  100. ^ Woodhill, Louis (4 November 2013). "Bitcoins Are Digital Collectibles, Not Real Money". Forbes. Retrieved 27 January 2014.
  101. ^ Vaishampayan, Saumya (9 January 2014). "Bitcoin now accepted on Overstock.com through VC-backed Coinbase". marketwatch.com. Wall Street Journal. Retrieved 10 February 2014.
  102. ^ Davidson, Kavitha (16 January 2014). "How Many Bitcoins for a Courtside Seat?". bloomberg.com. Bloomberg LP. Retrieved 20 January 2014.
  103. ^ Dahlberg, Nancy (23 January 2014). "TigerDirect.com to accept Bitcoin". Miami Herald Business. Miami Herald. Retrieved 26 January 2014.
  104. ^ "Clearly Canadian Joins Bitcoin Community". finance.yahoo.com. Yahoo! Finance. 2013-12-23. Retrieved 10 February 2104. {{cite web}}: Check date values in: |accessdate= (help)
  105. ^ Kharif, Olga (6 January 2014). "Bitcoin Tops $1,000 Again as Zynga Accepts Virtual Money". bloomberg.com. Bloomberg LP. Retrieved 20 January 2014.
  106. ^ Holpuch, Amanda (22 November 2013). "Virgin Galactic to accept Bitcoin for space flights". The Guardian. Retrieved 24 November 2013.
  107. ^ Vigna, Paul (22 November 2013). "The University of Bitcoin Rises in Cyprus". The Wall Street Journal. Retrieved 22 November 2013.
  108. ^ Strauss, Steven (14 April 2013). "Nine Trust-Based Problems With Bitcoin". The Huffington Post. Retrieved 20 October 2013.
  109. ^ Grocer, Stephen (2 July 2013). "Beware the Risks of the Bitcoin: Winklevii Outline the Downside". Moneybeat. Retrieved 21 October 2013.
  110. ^ O'Leary, Naomi (2 April 2012). "Bitcoin, the City traders' anarchic new toy". Reuters. Retrieved 14 November 2012.
  111. ^ Chirgwin, Richard (8 June 2011). "US senators draw a bead on Bitcoin". The Register. Retrieved 14 November 2012. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  112. ^ Tucker, Jeffrey (1 December 2013). "Ponzi Logic: Debunking Gary North". The Libertarian Standard. Retrieved 12 February 2014.
  113. ^ "Virtual Currency Schemes" (PDF). European Central Bank. October 2012. Retrieved 4 December 2012. {{cite journal}}: Cite journal requires |journal= (help)
  114. ^ European Central Bank (October 2012). "1". Virtual Currency Schemes (PDF). Frankfurt am Main: European Central Bank. p. 5. ISBN 978-92-899-0862-7. Retrieved 5 March 2014.
  115. ^ Financial Crimes Enforcement Network (21 July 2011). "Financial Crimes Enforcement Network". Bank Secrecy Act Regulations; Definitions and Other Regulations Relating to Money Services Businesses. Federal register. p. 76 FR 43585. Retrieved 6 March 2014. 31 C.F.R. § 1010.100(ff)(5)(i)(A)
  116. ^ "FIN-2013-G001: Application of FinCEN's Regulations to Persons Administering, Exchanging, or Using Virtual Currencies". Financial Crimes Enforcement Network. 18 March 2013. p. 6. Retrieved 4 March 2014.
  117. ^ Lee, Timothy (20 March 2013). "US regulator Bitcoin Exchanges Must Comply With Money Laundering Laws". Arstechnica. Bitcoin miners must also register if they trade in their earnings for dollars. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  118. ^ US Government Accountability Office (May 2013). "Virtual Economies and currencies: Additional IRS guidance could reduce tax compliance risks". GAO Report. Report to the Committee on Finance, U.S. Senat. {{cite web}}: |access-date= requires |url= (help); Missing or empty |url= (help)
  119. ^ "Guidance for a Risk-Based Approach: Prepaid Cards, Mobile Payments and Internet-based Payment Services" (pdf). Guidance for a risk-based approach. Paris: Financial Action Task Force (FATF). June 2013. p. 47. Retrieved 6 March 2014.
  120. ^ Duhaime, Christine. "Canada to Regulate Bitcoin, Digital Currencies and online casinos under its anti-money laundering and counter-terrorist financing laws". Retrieved 7 March 2014. Duhaime Law
  121. ^ Duhaime, Christine. "1st Canadian official regulatory response to Bitcoin highlights Ponzi scheme and money laundering risks". Retrieved 7 March 2014. Duhaime Law
  122. ^ http://www.commdiginews.com/business-2/business-cyberhighway/brand-com-blackmail-cyber-attack-shines-light-on-cybercrime-11690/
  123. ^ http://www.valuewalk.com/2014/03/mike-zammuto/
  124. ^ http://segment.com/mike-zammuto-cyber-attack-brand-com/
  125. ^ For obfuscation of transactions and seizure of bitcoins from black market Utopia, see Kelion, Leo (12 February 2014). "Five arrested in Utopia dark net marketplace crackdown". bbc.co.uk. BBC. Retrieved 13 February 2014.
  126. ^ For Bitcoin enthusiasts worries that the currency may be stigmatized as "drug barter tokens", see Chen, Adrian (1 June 2011). "The Underground Website Where You Can Buy Any Drug Imaginable". {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help). Gawker.
  127. ^ Sanati, Cyrus (18 December 2012). "Bitcoin looks primed for money laundering". money.cnn.com. CNN. Retrieved 18 October 2013.
  128. ^ Timothy B. Lee and Hayley Tsukayama (2 October 2013). "Authorities shut down Silk Road, the world's largest Bitcoin-based drug market". The Washington Post. Retrieved 21 October 2013.
  129. ^ "Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity" (PDF). Cyber Intelligence Section and Criminal Intelligence Section. FBI. 24 April 2012. Retrieved 20 October 2013.
  130. ^ For claim, see "Developing a More Open Economy". bitcoinfoundation.org. Bitcoin Foundation. Retrieved 4 March 2014.
    • For widespread theft, see "Bitcoin under pressure". economist.com. The Economist Newspaper Limited. 30 November 2013. Retrieved 4 March 2014. there have also been many cases of Bitcoin theft
  131. ^ "Monetarists Anonymous". The Economist. The Economist Newspaper Limited. 29 September 2012. Retrieved 21 October 2013.
  132. ^ Mardlin, John Jeffrey (2 October 2013). "How Will The FBI Shut Down Of Silk Road Affect Bitcoins?". Quora. Forbes. Retrieved 21 October 2013.
  133. ^ Geuss, Megan (24 August 2013). "Firm says online gambling accounts for almost half of all Bitcoin transactions". Ars Technica. Retrieved 21 October 2013.
  134. ^ Smith, Gerry (15 April 2013). "How Bitcoin Sales Of Guns Could Undermine New Rules". huffingtonpost.com. TheHuffingtonPost.com, Inc. Retrieved 20 October 2013.
  135. ^ a b Christin, Nicolas (2013). Traveling the Silk Road: A Measurement Analysis of a Large Anonymous Online Marketplace (PDF). Carnegie Mellon INI/CyLab. p. 8. Retrieved 22 October 2013.
  136. ^ Kaminska, Izabella (4 December 2013). "Capital controls, Bitcoin edition". FT Alphaville. Financial Times. Retrieved 28 January 2014.
  137. ^ a b "Silk Road 2 loses $2.7m in bitcoins in alleged hack". BBC News. 14 February 2014. Retrieved 15 February 2014.
  138. ^ Meiklejohn, Sarah; et al. (23 October 2013). "A Fistful of Bitcoins: Characterizing Payments Among Men with No Names" (PDF). Association for Computing Machinery (ACM). {{cite web}}: Explicit use of et al. in: |first= (help) Paper is explained by Kirk, Jeremy (28 August 2013). "Bitcoin offers privacy-as long as you don't cash out or spend it". PC World.
  139. ^ For FBI, see "Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity" (PDF). Cyber Intelligence Section and Criminal Intelligence Section. FBI. 24 April 2012. Retrieved 20 October 2013.
  140. ^ Spaven, Emily (23 July 2013). "SEC charges Texas man for defrauding investors in bitcoin Ponzi scheme". CoinDesk. Retrieved 7 March 2014.
  141. ^ a b "SEC charges Texas man with running Bitcoin-denominated Ponzi scheme" (Press release). US Securities and Exchange Commission. 23 July 2013. Retrieved 7 March 2014.
  142. ^ Jeffries, Adrianne (19 December 2013). "How to steal Bitcoin in three easy steps". The Verge. Retrieved 17 January 2014.
  143. ^ Scharr, Jill (4 December 2014). "Bitcoin Heist: Millions Vanish from Online Black Market". Tom's Guide. Retrieved 17 January 2014.
  144. ^ Everett, David. "So how can you steal Bitcoins". Smartcard & Identity News. Retrieved 17 January 2014.
  145. ^ Wheatley, Mike (5 December 2013). "Sheep Marketplace heist – $100M worth of Bitcoin believed stolen as site vanishes from the Deep Web". SiliconANGLE. Retrieved 10 January 2014.
  146. ^ a b Hern, Alex (9 December 2013). "Recovering stolen bitcoin: a digital wild goose chase". The Guardian. Retrieved 6 March 2014.
  147. ^ "Mt. Gox bitcoin exchange files for bankruptcy". Japan Herald. 28 February 2014. Archived from the original on 7 March 2014.[dead link]
  148. ^ a b Ligaya, Armina (5 March 2014). "After Alberta's Flexcoin, Mt. Gox hacked, Bitcoin businesses face sting of free-wheeling ways". Financial Post. Retrieved 7 March 2014.
  149. ^ a b c d Rizzo, Pete (4 March 2014). "Bitcoin bank Flexcoin to close after $600,000 bitcoin theft". CoinDesk. Retrieved 7 March 2014. Cite error: The named reference "rizzo2014" was defined multiple times with different content (see the help page).
  150. ^ a b c Truong, Alice (6 March 2014). "Another Bitcoin exchange, another heist". Fast Company. Retrieved 7 March 2014.
  151. ^ "Man Throws Away 7,500 Bitcoins, Now Worth $7.5 Million". CBS DC. 29 November 2013. Retrieved 23 January 2014.
  152. ^ Peter Coogan (17 June 2011). "Bitcoin Botnet Mining". Symantec.com. Retrieved 24 January 2012. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  153. ^ Goodin, Dan (16 August 2011). "Malware mints virtual currency using victim's GPU". The Register. Retrieved 10 January 201. {{cite news}}: Check date values in: |accessdate= (help)
  154. ^ "Infosecurity - Researcher discovers distributed bitcoin cracking trojan malware". Infosecurity-magazine.com. 19 August 2011. Retrieved 24 January 2012.
  155. ^ "Mac OS X Trojan steals processing power to produce Bitcoins - sophos, security, malware, Intego - Vulnerabilities - Security". Techworld. 1 November 2011. Retrieved 24 January 2012.
  156. ^ "E-Sports Entertainment settles Bitcoin botnet allegations". BBC News. 20 November 2013. Retrieved 24 November 2013.
  157. ^ a b Hajdarbegovic, Nermin (8 January 2014). "Yahoo infects 2 million European PCs with Bitcoin malware". CoinDesk. Retrieved 7 March 2014.
  158. ^ Hajdarbegovic, Nermin (5 December 2013). "German police detain 'Bitcoin mining hackers'". CoinDesk. Retrieved 7 March 2014.
  159. ^ "Euro exchange rates for 04/12/2013 (4 December 2013)". Exchange Rates UK. Retrieved 7 March 2014.
  160. ^ Hajdarbegovic, Nermin (22 January 2014). "Microsoft destroys Bitcoin mining botnet Sefnit". CoinDesk. Retrieved 7 March 2014.
  161. ^ a b c d Hajdarbegovic, Nermin (27 February 2014). "Nearly 150 strains of malware are after your bitcoins". CoinDesk. Retrieved 7 March 2014.
  162. ^ Finkle, Jim (24 February 2014). "'Pony' botnet steals bitcoins, digital currencies: Trustwave". Reuters. Retrieved 7 March 2014.
  163. ^ a b Southurst, Jon (10 February 2014). "'CoinThief' Mac malware steals bitcoins from your wallet". CoinDesk. Retrieved 7 March 2014.
  164. ^ a b c "How Ransomware turns your computer into a bitcoin miner". The Guardian. 10 February 2014. Retrieved 7 March 2014.
  165. ^ Gibbs, Samuel (21 November 2013). "US police force pay bitcoin ransom in Cryptolocker malware scam". The Guardian. Retrieved 7 March 2014.
Wikimedia Commons has media related to Bitcoin.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Bitcoin&oldid=599189428"