Police have dramatically increased their requests for personal cellphone information, according to data compiled by a Democratic congressman.
Wireless carriers responded in 2011 to 1.3 million law enforcement requests for people's cellphone information, including text messages, location data, call logs and "cell tower dumps," in which the wireless carriers provide police with all of the phone numbers that connected to a particular cell tower in a period of time.
Rep. Edward Markey (D-Mass.), who released the information on Monday, described the volume and scope of the requests as "startling."
Nine carriers provided reports to Markey after he questioned them in May about their compliance with police requests for data. It is the most complete account yet of how police collect cellphone information for investigations.
The wireless carriers said they provided some of the data in response to legal warrants, but that they also complied with many informal requests if the police said it was an emergency.
Markey, the co-chairman of the Bipartisan Congressional Privacy Caucus, sent letters to the carriers asking about their practices after The New York Times reported in March that cellphone tracking had become a "routine tool" of law enforcement.
The carriers told Markey that police requests have risen dramatically in recent years.
Verizon reported that requests have grown about 15 percent for each of the last five years, and T-Mobile said requests have increased about 12 to 16 percent every year.
The wireless companies said police agencies sometimes reimburse them for providing the information, but that compensation is inconsistent and complying with requests often imposes costs on the companies. They insisted that they are not "selling" their customers' information to police.
Cricket, a small wireless carrier, said it is "frequently not paid on the invoices it submits." The company said it hired an outside company, Neustar, to handle police requests.
Cellphones have become ubiquitous and can provide police with vital information for investigations that would have been inaccessible just a few years ago. Police can use location data to track kidnappers or identify who was at the scene when a crime was committed.
Requests for cellphone information such as location data have surpassed traditional surveillance technologies such as wiretaps. In 2010, there were only 3,000 wiretaps nationwide.
But civil liberties groups are concerned that there are not clear standards to protect people's private information from police surveillance.
“Whether they realize it or not, Americans are carrying tracking devices with them wherever they go. Today’s new information makes it clear that law enforcement has carte blanche to follow the trail they leave behind,” Christopher Calabrese, a lawyer for the American Civil Liberties Union (ACLU), said in a statement. “The cell phone data of innocent Americans is almost certainly swept up in these requests. Without clear safeguards and standards for how law enforcement gathers and stores location information, there is a massive privacy gap that leaves all of us vulnerable.”
Calabrese urged Congress to pass the GPS Act, a bill from Rep. Jason Chaffetz (R-Utah) and Sen. Ron Wyden (D-Ore.) that would require police to obtain a warrant before requesting location data from a person's cellphone, laptop or GPS device, except in an emergency.
The Supreme Court ruled in January in United States v. Jones that tracking a suspect's car with a GPS device qualifies as a "search" under the Fourth Amendment. But how that decision applies to cellphones and the extent of the requirements it imposes on police remain unclear.