British spies are believed to have been secretly accessing fibre-optic cables tapping into significant numbers of emails, Facebook messages, recorded phone calls, and other communications,.
Documents given to the Guardian by US whistleblower Edward Snowden suggest that data from the network of cables that carry global phone calls and internet traffic are being analysed by the GCHQ under codename 'Tempora'.
According to the newspaper the data has been shared with the National Security Agency in the US with the newspaper claiming that Tempora has been in operation for the last 18 months. The operation is understood to have lead to a number of high-profile arrests and convictions, including those of a terror cell in the Midlands and London-based individuals planning attacks on last year's Olympic Games.
The documents suggest that the GCHQ and NSA have the ability to access recordings of phone calls and user's entire internet history, with scans taking place on both targeted suspects and entirely innocent people. The Guardian has said the documents reveal that the GCHQ was handling around 600 million "telephone events" daily, and had tapped in excess of 200 fibre-optic cables processing data from at least 46 of them each time.
Snowden, who has left the US for Hong Kong, is quoted as saying: "It's not just a US problem. The UK has a huge dog in this fight. They (GCHQ) are worse than the US."
Cheltenham-based GCHQ has not commented but has said in terms of complying with the law the agency is "scrupulous".
BBC Breakfast is reporting this morning that the American authorities have filed charges of espionage and theft against Snowdon. The BBC has also said the US is believed to be preparing an expedition request.