Snowden reveals mass surveillance

A former contractor for the American National Security Agency has revealed himself as the source of leaks exposing mass surveillance of phone and internet communications by American and British intelligence agencies.

Edward Snowden, a 29-year-old computer specialist, identified himself in an interview with The Guardian newspaper published on 9 June, days after the first reports based on documents he supplied.

What was revealed

The documents show that the NSA has been collecting records of millions of telephone calls made by customers of the American phone company Verizon. Another programme, known as Prism, gives the agency access to data held by major internet companies including Google, Facebook, Apple and Microsoft.

The companies have denied giving the government direct access to their servers, and say they only hand over information when required by law.

Further reports have raised questions about the role of GCHQ, the British intelligence agency in Cheltenham, which works closely with the NSA.

Who is Snowden?

Snowden has worked for the Central Intelligence Agency and as a contractor for the NSA, most recently for the consultancy Booz Allen Hamilton in Hawaii. He flew to Hong Kong last month with a large number of classified documents.

He says he acted because he believed the public had a right to know what the government was doing in their name, and that the surveillance was a threat to privacy and freedom.

Reaction

The White House has defended the programmes, saying they are legal, overseen by courts and Congress, and have helped prevent terrorist attacks. Some politicians have called Snowden a traitor and demanded that he be prosecuted.

Civil liberties groups have praised him as a whistleblower and called for an inquiry into the scale of surveillance.

In Britain, the Foreign Secretary, William Hague, has said that GCHQ operates within the law and that law-abiding citizens have nothing to fear.

A debate on privacy

The revelations have sparked a worldwide debate about the balance between security and privacy in the internet age. Most people now carry out much of their lives online, through email, social networks and mobile phones, creating vast amounts of data about their activities.

Technology companies are under pressure to explain how they protect their users' data, and some are calling for more openness about government requests.

Snowden's whereabouts are unclear, and the American authorities are expected to seek his return.