U.K. GCHQ - Computer Definition
In the United Kingdom, one of a number of government agencies existing to deal with national security issues. These include the Government Communications Headquarters (GCHQ), the Secret Intelligence Service (MI6), and the Security Service (MI5). Using warrants to intercept telecommunications, all of these agencies are actively involved in gathering intelligence. These agencies can also request access to communications data on their own authority.
Statewatch. UK: Government Trying to Slip Through “Voluntary” Data Retention Rejected by Consultation Process. [Online, September, 2003.] Statewatch Website. http://www.statewatch.org/news/2003/sep/11atcs.htm.