File showing spy agency mining citizens' records likely to cause ire on left and right.

The Obama Administration was braced for a torrent of hostile questions yesterday following the apparent revelation that the National Security Agency has been data-mining the phone records of tens of millions of ordinary Americans.

Not to be confused with eavesdropping, or bugging the phones of those suspected of conspiring to commit a terrorist or criminal offence, a top-secret court order published by the Guardian appears to show that the NSA has been trawling the anonymous "metadata" of potentially billions of phone calls.

Americans might take comfort that the "internals" of their phone conversations - ie the voices themselves - are not being routinely recorded, but it seems from this leak that potentially everyone with a phone is under some surveillance in the US.

Studies have shown that while anonymous, the "metadata" - records of location data, call duration, unique identifiers - can provide a surprising amount of information very quickly when zeroed in on by investigators.


For Barack Obama - a President who prided himself on his liberal credentials - this leak is a potentially devastating revelation since it exposes him to attack on two fronts - both the libertarian right and the liberal left.

It is not clear how wide the NSA data-mining project goes, it's effectiveness as a counter-terrorism tool in identifying potential terrorist or criminal cells or whether it has been used for any other purposes. It appears from previous reports that the NSA's data-mining operation has long been suspected - but this is the first clear-cut proof, in the shape of a highly unusual leak from the secretive Foreign Intelligence Service Court (Fisa), that the practice is occurring. It also shows the Obama Administration has continued a practice begun under the Bush Administration.

A report in USA Today from 2006, quoting anonymous intelligence officials, alleged that the NSA been "secretly collecting the phone call records of tens of millions of Americans" and that the agency was using the data to "analyse calling patterns in an effort to detect terrorist activity".

Cindy Cohn, a lawyer at the Electronic Frontier Foundation, a civil liberties organisation that has accused the Government of operating a secret dragnet surveillance programme, told the Washington Post "I don't think Congress thought it was authorising dragnet surveillance" when it passed the 2001 Patriot Act.

Cohn said: "I don't think Americans think that's okay. I would be shocked if the majority of Congressmen thought it's okay."

Former Vice-President Al Gore tweeted: "In digital era, privacy must be a priority. Is it just me, or is secret blanket surveillance obscenely outrageous?"

Over the next few days and weeks, expect a fierce and polarising debate over just what Americans do feel is acceptable, in the name of their national security.