U.K. Secretary of State for the Home Department, Interception of Communications in the United Kingdom: A Consultation Paper (June 1999) (full-text).
All interception of the public telephone system in the U.K. takes place under a strict regime laid down by Parliament — principally the Interception of Communications Act 1985. But those who drafted that legislation some fifteen years ago could not and did not foresee the extraordinary pace of change in the communications industry. Faced with a revolutionised communications industry and dated legislation on interception, sophisticated criminals and terrorists have been quick to put the new technology to use. The law must be revised if we are to preserve the ability of the law enforcement and intelligence agencies to prevent and detect serious crime and threats to national security.