The statistics were compiled from letters Markey received from nine mobile carriers in response to requests for information from the lawmaker. The carriers were US Cellular, Sprint Nextel, T-Mobile USA, Leap Wireless/ Cricket Communications, MetroPCS, Verizon, AT&T, C Spire Wireless, and TracFone Wireless.
The information included geolocation information, text messages, and “cell tower dumps” in which carriers provide all the phones numbers of cell users that connect with a tower during a specific period of time. All requests were made pursuant to a legal warrant or granted due to an emergency situation in which an individual was in imminent danger, according to the carriers.
Verizon reported that there has been an annual increase of law enforcement requests of 15%, and T-Mobile reported an increase of 12–16%, according to the letters received by Markey.
In releasing the data, Markey said: "We cannot allow privacy protections to be swept aside with the sweeping nature of these information requests, especially for innocent consumers. Law enforcement agencies are looking for a needle, but what are they doing with the haystack? We need to know how law enforcement differentiates between records of innocent people, and those that are subjects of investigation, as well as how it handles, administers, and disposes of this information.”