Google has released figures on the number of requests to turn over data made by the U.S. Federal Bureau of Investigation (FBI), showing that it receives less than 1,000 requests a year.
Google receives thousands of requests from law enforcement authorities to hand over user data, and while the firm was one of the first to publish transparency reports, it took until today for Google to work out a way to publish statistics about National Security Letters.
The firm's figures show that it received less than 1,000 requests a year for the last four years, but it wasn't able to elaborate further due to restrictions placed by law enforcement agencies.
"The FBI has the authority to prohibit companies from talking about these requests," wrote Richard Salgado, legal director of Law Enforcement and Information Security at Google. "But we've been trying to find a way to provide more information about the NSLs we get-particularly as people have voiced concerns about the increase in their use since 9/11."
While Google didn't provide any real details outside of the range of NSL requests, showing that for the past four years it has received between zero and 999 National Security Letters.
Apparently these vague numbers were all that Google was allowed to publish, with Salgado saying, "This is to address concerns raised by the FBI, Justice Department and other agencies that releasing exact numbers might reveal information about investigations."
Google does provide more detailed data that is broken down into search warrants, subpeonas and "other" requests, reporting that in the six months ending December 2012 it received 8,438 requests for user data and 14,791 requests for users and accounts, and that it produced data for 88 percent of those requests.