LONDON — Britain’s top counterterrorism official says the country’s espionage rules allow its electronic spy agency to routinely intercept online communications between Britons who use US-based platforms such as Facebook, Twitter, and Google.
A witness statement by Office for Security and Counterterrorism chief Charles Farr, made public Tuesday, said data sent on those services is classed as ‘‘external’’ rather than ‘‘internal’’ communications because the companies are based outside Britain.
Britain’s Home Office confirmed the document was genuine. It was written in response to a legal action by civil liberties groups who are seeking to curb cyberspying, and was published by the groups on Tuesday.
Britain’s electronic intelligence agency, GCHQ, has broad powers to intercept communications outside the country, but needs a warrant and suspicion of wrongdoing to monitor Britons.
In the document, Farr said some internal communications are intercepted under the external rules, but they ‘‘cannot be read, looked at, or listened to’’ except in very limited circumstances. He said that was a ‘‘significant distinction.’’
Civil liberties organizations say the rules are too vague and allow for mass surveillance.
‘‘The security services consider that they’re entitled to read, listen, and analyze all our communications on Facebook, Google, and other US-based platforms,’’ said James Welch, legal director of Liberty, one of the groups involved in the legal action. ‘‘If there was any remaining doubt that our snooping laws need a radical overhaul, there can be no longer.’’