The UK government has been indiscriminately siphoning its citizens' electronic communications, it was revealed on Tuesday.

As a result of a legal challenge made by Privacy International and several other civil liberties organizations, Charles Farr, the director general of the Office for Security and Counter Terrorism, was forced to release details of a clandestine policy outlining the government's rationale for allowing the collection of UK citizens' communications via Facebook, Google, Yahoo, Twitter and YouTube.

The 48-page document for the first time discloses how GCHQ's mass interception program, code-named TEMPORA, skirts ill-defined legal guidelines by claiming the web services are "external communications" and therefore not covered under the nation's Regulation of Investigatory Powers Act, which stipulates a warrant be obtained before intercepting "internal" communications.

Privacy advocates argue the program violates citizens' rights and that legacy surveillance laws need an overhaul.