Type of site
Sheep Marketplace was an anonymous marketplace set up as a Tor hidden service. It launched in March 2013 and was one of the lesser known sites to gain popularity with the well publicized closure of the Silk Road marketplace later that year. It ceased operation in December 2013, when it announced it was shutting down after a vendor stole $6 million worth of users' bitcoins.
Bitcoin theft incident
In December 2013 Sheep Marketplace announced that one of the site's vendors exploited a vulnerability to steal 5400 bitcoins, valued at about $6 million at the time. According to Forbes and The Guardian, several users reported the site had started to block withdrawals of bitcoins more than a week prior to the theft. Users furthermore suggested the site's administrators held far more than 5400 bitcoins, pointing to records of a coincidental transfer of almost 40,000. As users in the site's forums began to complain and discuss the possibility of connivance, administrators took the forum offline.
Victims of the theft have attempted to identify the thief by sending "tagged" bitcoins to his accounts, using the public nature of bitcoin transactions to follow these moneys through the "blockchain" record of transfers. Within a couple days of the theft, a large amount of bitcoins were noticed being processed by Bitcoin Fog, a "tumbler" used to launder bitcoins by shuffling them between many accounts for a small fee. The size of the transaction, 96,000 bitcoins, caused Bitcoin Fog to fail, leaving the money traceable. Not long thereafter, the last known wallet of the user who had been presumed to be the thief was found to be a wallet owned by BTC-e, a large bitcoin currency exchange. This has led to speculation that the thief sent their money to the exchange in the hope of trading the coins for alternate crypto-currencies or moving to new wallets to further obfuscate their path.
In March 2015 Czech police arrested a man suspected to be the Sheep Marketplace thief when he paid for an expensive house entirely in bitcoins. A nine month investigation showed estimated that he had made $800,000 of sudden purchases. In October 2017 Tomáš Jiříkovský, the creator of the Sheep Marketplace, was sentenced to serve nine years in prison for stealing bitcoins from the market’s users. 
- "Archived copy". Archived from the original on 2017-07-08. Retrieved 2017-09-01.CS1 maint: Archived copy as title (link)
- O'Neill, Patrick Howell (27 March 2015). "Suspected Dark Net master thief busted trying to buy luxury Czech home". Daily Dot.
- Adrianne Jeffries (2013-04-29). "Drugs, porn, and counterfeits: the market for illegal goods is booming online". The Verge. Retrieved 2013-12-02.
- "Dark marketplace closes after theft of £3m in bitcoins". BBC News. 2013-12-02. Retrieved 2013-12-02.
- Mandala, Ravi (2013-12-01). "Silk Road-like Sheep Marketplace scams users; over 39k Bitcoins worth $40 million stolen". Techie News. Retrieved 2013-12-02.
- Green berg, Andy (2013-12-01). "Silk Road Competitor Shuts Down And Another Plans To Go Offline After Claimed $6 Million Theft". Forbes. Retrieved 2013-12-02.
- Hern, Alex (3 December 2013). "Online drugs marketplace shut down after £3.5m bitcoin hack". The Guardian. Retrieved 25 April 2014.
- Block chain record
- Sankin, Aaron (2 December 2013). "Sheep Marketplace scam reveals everything that's wrong with the Deep Web". Daily Dot.
- Edwards, Jim (2013-12-03). "A Thief Is Attempting To Hide $100 Million In Stolen Bitcoins — And You Can Watch It Live Right Now". SFGate. Retrieved 2013-12-04.
- "I just Chased him through a bitcoin tumbler, and when he Came out with 96,000 BTC, I was Waiting for Him..." Reddit. 2013-12-01. Retrieved 2013-12-04.
- Alex Hern. "Recovering stolen bitcoin: a digital wild goose chase | Technology". theguardian.com. Retrieved 2013-12-22.
- Blažek, Vojtěch (27 March 2015). "Jak se praly bitcoiny: Miliony z ciziny, vila napsaná na dědečka". Hospodářské Noviny.
- "Archived copy". Archived from the original on 2017-09-01. Retrieved 2017-09-01.CS1 maint: Archived copy as title (link)
- "Archived copy". Archived from the original on 2018-04-03. Retrieved 2018-04-02.CS1 maint: Archived copy as title (link)
- Shin, Laura (30 May 2016). "Mystery Solved: $6.6 Million Bitcoin Theft That Brought Down Dark Web Site Tied To 2 Florida Men". Forbes. Retrieved 1 June 2016.