The American Civil Liberties Union announced a new effort on Wednesday to uncover details on how local law enforcement agencies use location data stored on cell phones to track or provide evidence on private citizens.
Last month a top lawyer at the National Security Agency, Matthew Olsen, suggested the Patriot Act may have given the federal government powers to use cell phone data to track Americans inside the United States, a comment that alarmed privacy advocates and civil libertarians.
On Wednesday, 34 ACLU affiliates across the country cited Olsen's remarks and announced they had filed requests under government transparency laws for documents that could reveal how authorities use location data on cell phones for law enforcement.
The ACLU groups want to know if agencies provide citizens the appropriate protections when they access this data; for instance, they want to know if officers tend to obtain a warrant first. They are also seeking statistics on how often authorities use this data and how much funding these efforts receive.
"The ability to access cell phone location data is an incredibly powerful tool and its use is shrouded in secrecy. The public has a right to know how and under what circumstances their location information is being accessed by the government," Catherine Crump, staff attorney for the ACLU Speech, Privacy and Technology Project, said in a statement. "A detailed history of someone's movements is extremely personal and is the kind of information the Constitution protects."
The ACLU supports a bill under consideration in Congress that spells out clear guidelines on how government authorities may use location data from cell phones. Sen. Ron Wyden, D-Ore., and Rep. Jason Chaffetz, R-Utah, introduced the "Geolocation Privacy and Surveillance (GPS) Act" in June.
Privacy concerns related to cell phone use are not limited to questions about how the government may be tracking citizens. Reports earlier this year that revealed the extent to which smart phone companies track users' location were a major concern for privacy advocates.