BRUSSELS  -The European Commission has written to British Foreign Secretary William Hague demanding answers by the end of the week on leaked reports that Britain's spy services are tapping cables that carry the world's phone calls and Internet traffic.
"I have sent a letter to express my concern," the EU's Justice Commissioner Viviane Reding told a briefing on Wednesday, adding: "I have asked for a very urgent reply by the end of this week."
The claims, published by The Guardian newspaper, are based on leaked documents from US ex-intelligence technician Edward Snowden, who is now at a Moscow airport on the run from US authorities. The report on the British programme codenamed Tempora has sparked a fresh outcry from privacy campaigners.
German Justice Minister Sabine Leutheusser-Schnarrenberger said that if true it would be "like a nightmare out of Hollywood". Reding said she had asked Hague to clarify the extent of the programme, whether the data stayed in Britain or was passed to other countries, whether the spying was limited to individual cases and what the possibilities for legal redress were.
"It is a very clear signal that we need... the right balance between the protection of data and the processing of data for security reasons," Reding said.
The Guardian reported on Saturday that Britain's Government Communications Headquarters (GCHQ) has started processing vast amounts of personal information -- including Facebook posts, emails, Internet histories and phonecalls -- and was sharing it with its US partner the National Security Agency (NSA).
In reaction, however, GCHQ said it was "scrupulous" in its compliance with the law and declined to comment further.
Citing Snowden, The Guardian said that GCHQ was able to tap into and store data from the cables for up to 30 days.
The Guardian claimed Tempora had been running for 18 months and GCHQ and the NSA were able to access vast quantities of communications between entirely innocent people.
It also said that the intelligence-gathering directly led to the arrest and jailing of a British terror cell, the arrests of others planning acts of terror, and three London-based people planning attacks prior to the city's 2012 Olympic Games.
The Guardian said the documents it had seen showed that by last year, GCHQ was handling 600 million "telephone events" each day, had tapped more than 200 fibre-optic cables, and was able to process data from at least 46 of them at a time.