The 5th Circuit Court of Appeals in New Orleans sided with the Justice Department that "historical" records from cellphone towers showing the location of a phone are not protected by the Fourth Amendment, which prohibits unreasonable searches and seizures.
"The government does not require a member of the public to own or carry a phone," wrote Judge Edith Brown Clement in an opinion joined by Judge Dennis Reavley.
Clement said cellphone use is strictly voluntary along with the choice of a provider and the decision to make a call.
She said a user knows that a call "conveys cell site information," which the person voluntarily conveys each time he or she makes the call.
Privacy advocates argued that the proliferation of cell phones and new technologies permit law enforcement to track highly sensitive information about where individuals have been without showing a judge there is probable cause that a person has committed a crime.
The 2-1 ruling by the New Orleans appellate court involved three cases in which unknown federal agencies applied for 60 days of cellphone site-location data in criminal investigations.