The data, a response to a Congressional inquiry into cell phone surveillance, shows requests from federal state and local governments have soared over the past few years, with the companies fielding 1.3 million demands for private subscriber information in 2011 alone.

Government surveillance into cell phone use is a long-standing issue for privacy advocates, but even Congressmen are expressing shock at exactly how many such requests the companies are receiving.

At present there are very few legal restrictions on what the government can seek, with many agencies shifting away from wiretaps to more vague requests for data to avoid seeking a warrant. Many of the companies are keeping a team of lawyers on-hand to screen such requests, rejecting those they are worried might cause trouble for them later.