The Obama administration will be bracing itself for a torrent of hostile questions this morning 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 eaves-dropping, or bugging the phones of those suspected of conspiring to commit a terrorist or criminal offence, the 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.
On the one hand, American might take comfort that the 'internals' of their phone conversations – ie the voices themselves - are not being routinely recorded, but on the other, it seems from this leak that potentially everyone with a phone is under some form of surveillance in the USA.
Studies have shown that while anonymous, the 'metadata' – records of location data, call duration, unique identifiers – can provide a surprising amount of information, surprisingly quickly when zeroed in on by investigators.
For Mr 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 - from both the libertarian Right and the liberal Left.
Already the administration has been hammered over its aggressive prosecution of leakers, including what appeared to be an attempt to criminalise a Fox News journalist, James Rosen, for working a source to obtain a leak from the State Department about North Korea.
That story caused the New York Times – usually a reliable friend of the Obama administration - to write a seething editorial accusing the Department of Justice of over-reaching, and using its powers to send a "chilling" message to the media.
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 – indeed – whether it has been used for any other purposes.
It appears from previous reports that the NSA's data-mining operation is not new, and 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.
A report in USA Today newspaper 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 "analyze calling patterns in an effort to detect terrorist activity".
Since September 11 and the passing of the 2001 Patriot Act, the American public has accepted a great deal of inconvenience and intrusion in the name of national security. The publication of this court order will re-open the debate on how far the security services' writ should run.
Politically, the difficulty for Mr Obama is that even if the NSA is actually doing nothing different than it did for George W Bush, the American public – particularly on the liberal left – had believed that Mr Obama's administration represented a fundamental departure from the excesses of the Bush years.
Now, with the continued debate over the use of drones, the failure to close Guantanamo, the ultra-aggressive prosecution of leaks even to the point, perhaps, of muzzling a free press – the questions from the public and the media are starting to weigh down on the Obama White House.
Already last night, within hours of publication, civil liberties groups who have long warned about the extent of secret surveillance, were jumping on the revelations.
"This confirms what we had long suspected," says Cindy Cohn, an attorney at the Electronic Frontier Foundation (EFF), a civil liberties organization that has accused the government of operating a secret dragnet surveillance program told the Washington Post.
"I don't think Congress thought it was authorizing dragnet surveillance" when it passed the Patriot Act, Ms Cohn said, "I don't think Americans think that's OK. I would be shocked if the majority of Congressmen thought it's okay." Over the next few days and weeks, expect a fierce and polarizing debate over just what Americans do feel is acceptable, in the name of their national security.
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