Tuesday a federal appeals court in Philadelphia ruled that--in most cases--the FBI and other police agencies do not need a search warrant in order to track the location of cell phones used by Americans.
The three-judge panel of the Third Circuit sided with the Obama Administration (pdf) in the belief that a signed search warrant--one based on a probable cause to suspect criminal activity--isn't necessary when obtaining logs from wireless carriers that depict the whereabouts of a cell phone.
However the panel also sided with civil-liberties groups and decided that, in some cases, investigators will still need to obtain a search warrant from the lower courts to avoid potentially unconstitutional seizures of location data. The court said that this option would be used "sparingly."
Currently there's still a debate on whether the Fourth Amendment applies to phone records. "This decision does not definitively answer the question of the Fourth Amendment status of cell phone [location records]," said Electronic Frontier Foundation attorney Kevin Bankston.
Controversy surrounding the original drug-related case sparked when U.S. Magistrate Judge Lisa Lenihan said that the Justice Department could not obtain stored location data without a search warrant, citing federal privacy laws. Lenihan demanded that the Justice Department show probable cause.
The Obama Administration retaliated, indicating that warrantless tracking was permissible because Americans enjoy no "reasonable expectation of privacy" in their location--or at least in regards to cell phone use. The Administration said that it only needs a 2703(d) order to obtain the information--this requires law officials to show that the records are relevant and material to an ongoing criminal investigation.
For the Electronic Frontier Foundation and other privacy groups, the ruling is seen as a victory because some cases will still require a warrant. "Although the court did not definitively rule on the Fourth Amendment status of cell phone location information, it made clear that under some circumstances the privacy of such data could be constitutionally protected, and that judges have the discretion to require a warrant to avoid potentially unconstitutional seizures of location data," Bankston said.