A federal appeals court on Tuesday ordered the Justice Department to turn over information about cases where the government accessed cellphone location data without a warrant.
The court's decision was a victory for the American Civil Liberties Union, which first requested the information four years ago.
A three-judge panel of the U.S. Court of Appeals for the District of Columbia ordered the Justice Department to reveal the names and docket numbers of cases that resulted in a conviction or guilty plea in which the government accessed location data. The court did not grant the ACLU's request to reveal information about cases that did not result in a conviction.
Charles Miller, a Justice Department spokesman, said the agency is reviewing the decision and has not decided whether to appeal.
According to the ACLU, the government has been gathering information about suspects' locations using the data on their cellphones. The law enforcement agencies have been receiving a judge's approval before accessing the data but have not been required to show probable cause, as is usually required for a warrant.
"Today's decision is a significant victory in the fight against warrantless tracking of Americans by their government," wrote Jay Stanley, a senior policy analyst for the ACLU, in a blog post on Tuesday. "There is no good reason for DOJ to keep this case information secret, except to keep the American people in the dark about what its own government is doing and stifle debate about the new tracking powers the government is claiming."
The ACLU filed a request in 2007 under the Freedom of Information Act for details about cases where the government accessed tracking data. The Justice Department has fought the release of the information, arguing it would violate the privacy of the suspects under investigation.
"Everyone acknowledges that the government has a right to keep the details of particular investigations secret, but when the government adopts whole new policies that affect our society’s privacy rights in very broad ways — that is something that should be decided democratically, and that can’t happen if we don’t even know what’s happening," Stanley wrote.
The Supreme Court is set to hear a related case later this year about whether police can put Global Positioning System devices on people's cars without a warrant.