Following whistleblower Edward Snowden’s leaks of National Security Agency documents pointing to mass online surveillance, both Facebook and Microsoft have released details on the number of legal orders made to them by the NSA.

Only a few days after revelations of the surveillance program known as PRISM, which alleged major companies such as the social networking giant Facebook and software maker Microsoft, as well as others, had provided the NSA direct access to their server data, both companies released statements denying such involvement.

On Friday both Microsoft and Facebook released more information regarding requests made by federal, state and local police in an effort to reassure users. The new information provided by Facebook and Microsoft detail the number of legal orders they received to disclose user data.

According to Microsoft, in the last six months of 2012 it received between 6,000 and 7,000 criminal and national security warrants, subpoenas and orders affecting between 31,000 and 32,000 consumer accounts.

Facebook, meanwhile, has divulged a similar number of requests during the same period of time.

“For the six months ending December 31, 2012, the total number of user-data requests Facebook received from any and all government entities in the U.S. (including local, state, and federal, and including criminal and national security-related requests) - was between 9,000 and 10,000. These requests run the gamut - from things like a local sheriff trying to find a missing child, to a federal marshal tracking a fugitive, to a police department investigating an assault, to a national security official investigating a terrorist threat. The total number of Facebook user accounts for which data was requested pursuant to the entirety of those 9-10 thousand requests was between 18,000 and 19,000 accounts,” said Facebook.

According to Facebook, then, the number of data requests made by law enforcement and intelligence services represent a “tiny fraction of one percent of our user accounts.”

Along with other implicated companies, such as Yahoo and Google, Microsoft and Facebook sought greater leeway from the government to disclose information regarding secret court orders compelling them to hand over user data, ostensibly in the interests of national security.

According to James Clapper, head of US national intelligence, Internet companies implicated under the PRISM program were receiving legal orders sent to them "pursuant to Section 702 of the Foreign Intelligence Surveillance Act." In theory, judges must evaluate whether a request is "reasonably designed" to exclude Americans.

Without exception all of the companies tied to the PRISM leak maintained that they were only complying with orders made under the FISA Amendments Act, which established certain limits placed on a Bush-era warrantless surveillance following that scandal. Of course, critics argue that such courts are hand-picked and merely rubber-stamp requests that enable mass surveillance.

One such critic, retired US District Judge Nancy Gertner, told a panel discussion on constitutional privacy protection on Friday that the selection process for federal judges serving on such secret courts is extremely biased.

“It’s an anointment process. It’s not a selection process. But you know, it’s not boat rockers. So you have a [federal] bench which is way more conservative than before. This is a subset of that. And it’s a subset of that who are operating under privacy, confidentiality, and national security. To suggest that there is meaningful review it seems to me is an illusion,” says Gertner. 

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