After reaching an agreement with the Department of Justice last week, several major tech companies have released the first details about how many information requests they receive from intelligence agencies. Microsoft, Google, LinkedIn, Facebook, and Yahoo have all reported the numbers for national security letters (NSLs) and requests made under the Foreign Intelligence Surveillance Act.

The numbers given are far from exact. If companies want to split NSLs and FISA requests into separate categories, they can only reveal them in bands of 1,000; if they combine everything into one class, they can report them in bands of 250. LinkedIn and Apple, which published its report last week, chose the latter option: both said they had received between 0 and 249 total national security orders over the first half of 2013, requesting information about between 0 and 249 accounts. The other companies, all of which have much larger web presences and receive a higher volume of overall law enforcement requests, opted to split requests into separate categories with wider bands.

The reports cover three categories: NSLs, FISA requests for metadata like account details, and FISA requests for actual content. No company listed getting more than 999 orders in six months for any one category, though some reports go back a lot further than others. Google has been tracking requests the longest, with data going back to 2009. Microsoft started in 2011, and Facebook began in 2012; Yahoo's report only goes back to the beginning of 2013.

National security letters, January - June 2013

Number of requests Accounts covered Microsoft 0 - 999 0 - 999 Yahoo 0 - 999 0 - 999 Google 0 - 999 0 - 999 Facebook 0 - 999 0 - 999

When it comes to listing how many accounts the national security orders covered, the numbers give us a better sense of scale. In the first six months of 2013, for example, Microsoft received between 0 and 999 FISA orders requesting content from between 15,000 to 15,999 accounts. Facebook received between 0 and 999 requests for content from 5,000 to 5,999 accounts, Yahoo got orders covering 30,000 to 30,999 accounts, and Google had requests for 9,000 to 9,999 accounts. Requests for non-content information covered far fewer accounts, as did national security letters.

FISA requests, January - June 2013

Requests for content Accounts covered Non-content requests Accounts covered Microsoft 0 - 999 15,000 - 15,999 0 - 999 0 - 999 Yahoo 0 - 999 30,000 - 30,999 0 - 999 0 - 999 Google 0 - 999 9,000 - 9,999 0 - 999 0 - 999 Facebook 0 - 999 5,000 - 5,999 0 - 999 0 - 999

The above companies filed suit against the US government last year, saying they had the right to publish information about national security requests in broad numbers. But they withdrew their complaints after striking this deal, although it doesn't go as far as any of the parties involved were hoping. President Obama has also ordered a loosening of the secrecy requirements surrounding national security requests as part of overall surveillance reform.