SAN FRANCISCO - Internet titans eager to regain the trust of users for the first time on Monday provided insight into numbers of secret requests for user data made by the US government.
Disclosures from Google, Facebook and others came a week after US authorities agreed to give technology firms the ability to publish broad details of how their customer data has been targeted by US spy agencies.
The agreement came amid litigation from tech giants Facebook, Google, LinkedIn, Microsoft and Yahoo.
The companies have been seeking the right to release figures on vast surveillance of online and phone communications, in the wake of leaked documents from former National Security Agency contractor Edward Snowden.
US officials used the authority of the Foreign Intelligence Surveillance Act (FISA) to ask for information from between 9,000 and 10,000 Google user accounts in the first six months of 2013, and between 12,000 to 13,000 accounts in the six months prior to that, according to a blog post by Google.
Release of such data was subject to a six-month delay under the terms of an arrangement with the US Department of Justice letting Internet firms be slightly more open about how much information is sought under authority of FISA court orders.
"Publishing these numbers is a step in the right direction, and speaks to the principles for reform that we announced with other companies last December," Google law enforcement and information security legal director Richard Salgado said in a blog post.
"But we still believe more transparency is needed so everyone can better understand how surveillance laws work and decide whether or not they serve the public interest."
Google included the FISA request numbers in a routinely released Transparency Report about efforts by governments to legally obtain data from the California-based Internet titan.
Facebook on Monday disclosed it received FISA requests for information from accounts of 5,000 to 6,000 of its more than one billion members in the first six months of last year, and from the accounts of 4,000 to 6,000 of its users in the prior six months.
Meanwhile, Microsoft general counsel Brad Smith said in a blog post that FISA orders were used to demand information from between 15,000 to 16,000 accounts of users in the first six months of last year.
Yahoo, meanwhile, revealed that in the same time period US officials wielding FISA court authority came looking for information from 30,000 to 31,000 accounts.
The Sunnyvale, California-based company was quick to stress that while in the tens of thousands, the number of accounts targeted with FISA requests made up less than one-hundredth of one per cent of its global user base.
Apple last week disclosed that in the first half of last year it received 249 or fewer FISA or National Security Letter requests for information about users of services provided by the maker of iPhones, iPads, iPods and Macintosh computers.
Cupertino, California-based Apple said in a written post that information targeted in National Security Letters involved transactional data such as people's contact information and not content.
Yahoo, Facebook, Google and others promised to routinely update the FISA request figures, and to continue pressing for legal reform to share more information with users.
Currently, Internet firms are allowed only to provide ranges of FISA request numbers and barred from disclosing details regarding what was asked for or from whom.
"As we have said before, we believe that while governments have an important responsibility to keep people safe, it is possible to do so while also being transparent," Facebook legal counsel Colin Stretch said in a blog post.
"We will continue to advocate for reform of government surveillance practices around the world, and for greater transparency about the degree to which governments seek access to data in connection with their efforts to keep people safe."