The American Civil Liberties Union (ACLU) and the Electronic Frontier Foundation (EFF) are asking a federal court to order the U.S. Department of Justice to turn over records about the agency's tracking of mobile phone users.

The two civil liberties groups filed a lawsuit Tuesday in U.S. District Court for the District of Columbia, saying U.S. residents should have a right to know the extent of mobile phone tracking done by U.S. attorneys offices.

In the past year and a half, multiple news reports and court cases have revealed that some U.S. attorneys were claiming not to need probable cause of a crime in order to track people using mobile phones, the groups say in their complaint. In some cases, U.S. attorneys have bypassed court-ordered warrants, with law enforcement agents obtaining "tracking data directly from mobile carriers without any court involvement," the complaint says.

"The information now in the public domain suggests that [the DOJ] may be engaging in unauthorized and potentially unconstitutional tracking of individuals through their mobile phones," the ACLU and EFF said in their complaint. "Information pertaining to the DOJ's procedures for obtaining real-time tracking information is vital to the public's understanding of the privacy risks of carrying a mobile phone and of, more generally, the government's expansive view of its surveillance powers."

The ACLU filed a request for information on the tracking program, under the U.S. Freedom of Information Act, in November, but the DOJ has not yet delivered the documents requested, the group said.

"This is a critical opportunity to shed much-needed light on possibly unconstitutional government surveillance techniques," Catherine Crump, staff attorney with the ACLU, said in a statement. "Signing up for cell phone services should not be synonymous with signing up to be spied on and tracked by the government."

A DOJ spokesman declined to comment specifically on the lawsuit, but he seemed to dispute the reports that DOJ officials were requesting tracking information without court orders.

"It is important to remember that the courts determine whether or not cell-site data or more precise cell location data can be turned over to law enforcement in a particular case," said Dean Boyd, a spokesman for the DOJ's National Security Division. "Law enforcement has absolutely no interest in tracking the locations of law abiding citizens. Instead, law enforcement goes through the courts to lawfully obtain data to help locate criminal suspects, sometimes in cases where lives are literally hanging in the balance, such as a child abduction case or a serial murderer on the loose."

The IDG News Service is a Network World affiliate.