06/17/2014 -A federal appeals court has ruled that tracking Americans� movements using data from their cell phones without a warrant violates their Fourth Amendment rights. The court held that the government�s warrantless gathering of an individual�s cell phone site location information violated his reasonable expectation of privacy.

�While it may be the case that�GPS location information on an automobile would be protected only in the case of aggregated data, even one point of cell site location data can be within a reasonable expectation of privacy,� the U.S. Court of Appeals for the Eleventh Circuit wrote in its opinion onUnited States v. Davis. Instead, cell site information �is private in nature rather than being public data that warrants privacy protection only when its collection creates a sufficient mosaic to expose that which would otherwise be private.�

The court�s ruling stems from a case involving Quartavius Davis, who was charged and convicted of violating the Hobbs Act when he robbed a series of businesses, including a Little Caesars, a Walgreens, and a Wendy�s, in conspiracy with several other individuals.

As part of its evidence, the prosecution used records from cell phone service providers that showed Davis and his co-defendants had made and received phone calls near the locations of six businesses that they were charged with robbing. However, the location data had been obtained by a court order�not by a warrant�and Davis claimed that this action violated his Fourth Amendment rights. He requested that the evidence be suppressed during the trial, but his request was dismissed.

Instead, the prosecution used the cell phone site location data in the trial and Davis was convicted. He appealed the decision, which reached the U.S. Court of Appeals for the Eleventh Circuit. As part of his appeal, he again argued that his Fourth Amendment rights had been violated because the prosecution was able to use records collected from cell phone service providers without a warrant.

The appeals court did not overturn Davis�s sentencing, but it did rule that the government had violated his Fourth Amendment rights because �the government�s warrantless gathering of his cell site location information violated his reasonable expectation of privacy.�

The court asserted this position, despite the United States arguing that cell site location information is less protected than GPS data because it is less precise. �We do not doubt that there may be a difference in precision, but that is not to say that the difference in precision has constitutional significance,� the court wrote.

The court also held that the prosecutor during Davis�s trial had �stressed� that his cell phone use put him near six of the crime scenes. �While committing a crime is certainly not within a legitimate expectation of privacy, if the cell site location data could place him near those scenes, it could place him near any other scene,� the court explained. �There is a reasonable privacy interest in being near the home of a lover, or a dispensary of medication, or a place of worship, or a house of ill repute�.that information obtained by an invasion of privacy may not be entirely precise does not change the calculus as to whether obtaining it was in fact an invasion of privacy.�

Despite finding that Davis� Fourth Amendment rights had been violated, the appeals court did not find that the district court had committed a �reversible error.� Instead, the appeals court said that the officers who obtained Davis� cell site location data �acted in good faith reliance on an order rather than a warrant,� and had a sworn duty to carry out a court order to retrieve that data.

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