British spy agency Government Communications Headquarters operates a unit that targets hacktivists such as Anonymous and launches denial of service attacks to disrupt their communications, the latest leak from former United States National Security Agency contractor Edward Snowden shows.

First reported by NBCNews, a presentation from 2012 by the GCHQ at an NSA SIGDEV conference talks about a hitherto unknown unit of the British spy agency, the Joint Threat Research Intelligence Group, or JTRIG.
JTRIG has infiltrated Internet Relay Chat (IRC) rooms to identify hacktivists and helped to send hacker Edward Pearson to prison for more than two years for stealing identities and Paypal accounts.
However, JTRIG went beyond intelligence gathering and infiltration in its efforts to disrupt Anonymous.
Through unknown means, JTRIG launched distributed denial of service (DDoS) attacks to swamp the IRC network used by the hacktivists.
JTRIG's denial of service operation was declared a success and the agency boasted that 80 percent of IRC members had dropped out of the IRC channels a month after the attacks started.
Denial of service attacks are illegal in the UK, and the leaked documents are the first evidence of a Western government using them against political and other targets on the Internet.
GCHQ issued a statement to NBCNews, saying that all its work is carried out in accordance to "a strict legal and policy framework" and subject to rigorous oversight by UK government ministers, commissioners and parliamentary committees.
Other commenters questioned the amount of time and effort spent on chasing teenage hacktivists, with former White House cyber security official Jason Healey telling NBCNews that the GCHQ's DDoS attack was silly and only served to justify Anonymous activities.
The JTRIG presentation is marked "TOP SECRET/COMINT/REL TO USA, AUS, CAN, GBR, NZL", indicating it could be viewed by agencies in the so-called Five-Eyes intelligence sharing agreement, which includes Australia and New Zealand.