RICHMOND, Va. - In a decision that increases the possibility that the Supreme Court may take up the issue of warrantless phone tracking, the 4th U.S. Circuit Court of Appeals ruled today that the Fourth Amendment requires law enforcement to obtain a warrant before seeking a person’s historical cell phone location information from that person’s cell phone company.

In the case, United States v. Graham, the government obtained 221 days, or seven months, of historical cell phone location data for two suspects using a simple court order instead of a warrant based on probable cause. For one suspect, Aaron Graham, the records included 29,659 separate location data points, revealing countless private details of his movements and activities.

“Today’s opinion is a full-throated defense of Fourth Amendment privacy rights in the digital age. Cell phone location records can reveal some of the most private details about our lives by showing where we go and who we spend time with,” said Nathan Freed Wessler, staff attorney with the ACLU Speech, Privacy, and Technology Project. “Requiring a warrant for access to this information is an important protection against unjustified government intrusions.”

The 4th Circuit’s opinion holds that this information is protected by the Fourth Amendment because it can reveal private details of movements over time and locations inside of homes and other constitutionally protected spaces. The court rejected the government’s argument that people give up their privacy rights in this information because their cell phone companies have access to it. “People cannot be deemed to have volunteered to forfeit expectations of privacy by simply seeking active participation in society through use of their cell phones,” the decision reads.

Today’s decision reaches the opposite conclusion from the 5th and 11th Circuit Courts of Appeals, which have held that the Fourth Amendment does not protect cell phone location information from warrantless search. Just last week, the ACLU, along with attorneys in Florida, filed a petition with the Supreme Court seeking review of the 11th Circuit’s opinion in United States v. Davis.

The ACLU, the ACLU of Maryland, Center for Democracy & Technology, Electronic Frontier Foundation, and National Association of Criminal Defense Lawyers filed an amicus brief in U.S. v. Graham.

Today’s ruling is at: https://www.aclu.org/sites/default/files/field_document/graham_opinion_4th_cir.pdf

More information on the case is at: https://www.aclu.org/blog/fighting-striking-case-warrantless-cell-phone-tracking

This press release is available at: https://www.aclu.org/news/federal-appeals-court-rules-warrant-required-cell-phone-location-tracking