China is both the world's second-largest economy and a nuclear weapons state with the world's second-largest defense budget. Chinese Information Operations and Information Warfare includes the concept of “network warfare”, which is roughly analogous to the United States concept of cyber-warfare. Foreign Policy magazine provided an estimated range for China's "hacker army" personnel, anywhere from 50,000 to 100,000 individuals.
Western countries have long accused China of aggressive espionage, and while investigations have traced various attacks on corporate and infrastructure computer systems to have originated in China, "it is nearly impossible to know whether or not an attack is government-sponsored because of the difficulty in tracking true identities in cyberspace." China has denied these accusations of cyber-warfare and has, in turn, accused the United States of engaging in cyber-warfare against China - a claim the US government denies.
While some details remain unconfirmed, it is understood that China organizes its resources as follows:
- “Specialized military network warfare forces” (Chinese: 军队专业网络战力量) - Military units specialized in network attack and defense.
- "PLA - authorized forces” (授权力量) - network warfare specialists in the Ministry of State Security (MSS) and the Ministry of Public Security (MPS).
- “Non-governmental forces” (民间力量) - civilian and semi-civilian[definition needed] groups that spontaneously engage in network attack and defense.
In response to claims that Chinese universities, businesses, and politicians have been subject to cyber espionage by the United States National Security Agency since 2009,  the PLA announced a cyber security squad in May 2011 to defend their own networks.
Accusations of espionage
Organizations, companies, and governments in multiple countries have alleged incidents of hacking or espionage committed by China.
Officials in the Canadian government claimed that Chinese hackers compromised several departments within the federal government in early 2011, though the Chinese government has denied involvement.
Officials in the Indian government believe that attacks on Indian government networks, such as the attack on the Indian National Security Council, have originated from China. According to the Indian government, Chinese hackers are experts in operating botnets, of which were used in these attacks.
The United States of America has accused China of cyberwarfare attacks that targeted the networks of important American military, commercial, research, and industrial organisations. A Congressional advisory group has declared China "the single greatest risk to the security of American technologies" and "there has been a marked increase in cyber intrusions originating in China and targeting U.S. government and defense-related computer systems".
In January 2010, Google reported targeted attacks on its corporate infrastructure originating from China "that resulted in the theft of intellectual property from Google." Gmail accounts belonging to two human rights activists were compromised in an attack on Google's password system. American security experts connected the Google attack to various other political and corporate espionage efforts originating from China, which included spying against military, commercial, research, and industrial corporations. Obama administration officials called the cyberattacks "an increasingly serious cyber threat to US critical industries." 
In addition to Google, at least 34 other companies have been attacked. Reported cases include Northrop Grumman, Symantec, Yahoo, Dow Chemical, and Adobe Systems. Cyber-espionage has been aimed at both commercial and military interests.
China has denied accusations of cyberwarfare, and has accused the United States of engaging in cyber-warfare against it, accusations which the United States denies. Wang Baodong of the Chinese Embassy in the United States responded that the accusations are a result of Sinophobic paranoia. He states that "China would never do anything to harm the sovereignty or security of other countries. In conformity with such national policies, the Chinese government has never employed, nor will it employ so-called civilian hackers in collecting information or intelligence of other countries. Allegations against China in this respect are unwarranted, which only reflect the dark mentality of certain people who always regard China as a threat."
During March 2013, high-level discussions continued.
In May 2014, a Federal Grand Jury in the United States indicted five PLA Unit 61398 officers on charges of theft of confidential business information from U.S. commercial firms and planting malware on their computers.
In September 2014, a Senate Armed Services Committee probe revealed hackers associated with the Chinese government committing various intrusions of computer systems belonging to U.S. airlines, technology companies and other contractors involved with the movement of U.S. troops and military equipment, and in October 2014, The FBI added that hackers, who they believe to be backed by the Chinese government, have recently launched attacks on U.S. companies.
In 2015, the U.S Office of Personnel Management (OPM) announced that it had been the target of a data breach targeting the records of as many as 21.5 million people. The Washington Post reported that the attack came from China, citing unnamed government officials. FBI director James Comey explained "it is a very big deal from a national security perspective and a counterintelligence perspective. It's a treasure trove of information about everybody who has worked for, tried to work for, or works for the United States government."
In 2019, a study showed continued attacks on the US Navy and its industrial partners.
During 18 minutes on April 8th, 2010, state-owned China Telecom advertised erroneous network routes that instructed "massive volumes" of U.S. and other foreign Internet traffic to go through Chinese servers. A US Defense Department spokesman told reporters that he did not know if "we've determined whether that particular incident ... was done with some malicious intent or not" and China Telecom denied the charge that it "hijacked" U.S. Internet traffic.
- 2011 Canadian government hackings
- Beijing–Washington cyber hotline
- Chinese intelligence activity abroad
- Cyber-warfare by Russia
- Death of Shane Todd
- Google China
- Honker Union
- Operation Aurora
- Operation Shady RAT
- Titan Rain
- People's Liberation Army Strategic Support Force
- PLA Unit 61398
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