American tech giants - Microsoft and Facebook - have disclosed the number of requests they had received from the US National Security Agency to reveal details including internet usage of their consumers.

Social networking site Facebook said that in the last six months of 2012 its requests totaled between 9,000 and 10,000, and covered issues like local law enforcement investigating a child abduction case all the way through investigations into terrorist threats.

These requests spanned between 18,000 and 19,000 Facebook accounts, the company said.

Microsoft's total was about 32,000 accounts over the same six month period ending
December 31, 2012.

"For the six months ended December 31, 2012, Microsoft received between 6,000 and 7,000 criminal and national security warrants, subpoenas and orders affecting between 31,000 and 32,000 consumer accounts from US governmental entities (including local, state and federal)," said John Frank, vice president & deputy general counsel, Microsoft.

As such both Facebook and Microsoft said that this only impacts a "tiny fraction" of their global customers.

Their disclosure came following whistleblower Edward Snowden's leaks of documents which alleged major companies had provided the NSA direct access to their server data.

Following the disclosure, the tech giants including Google sought permission from the US to make public the request they received under the secretive internet spying programme of the NSA.

Microsoft and Facebook said they received only limited permission to release the information.

US President Barack Obama and other top US officials have defended the controversial surveillance into telephone records of millions of Americans and foreigners' Internet use, saying it had been critical in thwarting potential terror attacks.

"We are permitted to publish data on national security orders received (including, if any, Foreign Internet Surveillance Act Orders and FISA Directives), but only if aggregated with law enforcement requests from all other US local, state and federal law enforcement agencies; only for the six-month period of July 1, 2012 through December 31, 2012; only if the totals are presented in bands of 1,000; and all Microsoft consumer services had to be reported together," Frank said.

"As of today, the government will only authorise us to communicate about these numbers in aggregate, and as a range. This is progress, but we're continuing to push for even more transparency, so that our users around the world can understand how infrequently we are asked to provide user data on national security grounds," said Ted Ullyot, Facebook General Counsel.

The Government permission in this regard comes days after Google wrote to Attorney General Eric Holder and FBI Director Robert Mueller to publish information on such requests.

Google's chief legal officer David Drummond noted that the government should be able to "publish in our Transparency Report aggregate numbers of national security requests, including FISA disclosures - in terms of both the number we receive and their scope."

Google's numbers would clearly show that its compliance with these requests falls far short of the claims being made.
"Google has nothing to hide," he said.