In a closely-watched case out of Miami, the Eleventh Circuit Court of Appeals redefined the zone of privacy for cell phone users. As the Tech World was focused on Miami for the second annual eMerge conference, the court issued an opinion permitting prosecutors to obtain records from mobile carriers—without a search warrant—allowing the tracking of an individual’s movements through his or her cell phone’s interaction with cell towers.

In U.S. v. Davis, the Eleventh Circuit, sitting en banc, considered the appeal of Quartavious Davis who was convicted by a Miami jury of participating in seven armed robberies. At trial, the prosecution presented accomplice and eye witness testimony that Davis was involved in seven separate armed robberies in a two-month period. The prosecutors also introduced historical cell tower records obtained from Davis’ mobile carrier for the time period spanning the robberies. The records contained a history of numbers dialed by Davis and the cell tower that connected each call. The prosecutors called a police officer that was able to pinpoint on a map the exact location of each robbery and—using the data obtained from Davis’ mobile carrier—the location of the cell tower that connected Davis’ calls around the time of each robbery. While Davis’ location was not precise, the evidence gave the government a basis to argue that the calls to and from Davis’ cell phone were connected through cell tower locations near the robbery locations. Several witnesses testified that Davis used his cell phone around the time of the robberies. These facts allowed the prosecutors to assert that Davis was necessarily near the locations of the robberies at the times they occurred.

The government acquired Davis’ mobile carrier’s records pursuant to the Stored Communications Act (the “SCA”), under which a governmental entity may require a telephone service provider to disclose “a record … pertaining to a subscriber to or a customer of such service (not including the contents of communications) … if a court of competent jurisdiction” finds “specific and articulable fact showing that there are reasonable grounds to believe” that the records sought are “relevant and material to an ongoing investigation.” Importantly, the government is not required to show probable cause—as it would to obtain a search warrant—before a court will issue an order mandating the release of the records.

Following the guilty jury verdict, Davis appealed on the grounds that that the government violated his Fourth Amendment rights by obtaining his mobile carrier’s records without a search warrant and a showing of probable cause.

The Eleventh Circuit rejected Davis’ arguments on two independent grounds. First, the court held that the government’s acquisition of Davis’ mobile carrier’s records did not constitute a search for purposes of the Fourth Amendment. The court reasoned that Davis did not have ownership or possession of the records, and, moreover, Davis did not have a reasonable expectation of privacy in records of the transmissions between his cell phone and his mobile carrier’s cell phone towers—particularly given that it was information captured in the mobile carrier’s records. Second, the court found that even if the government’s acquisition of the mobile carrier’s records did constitute a search under the Fourth Amendment, the government’s acquisition of the information was nonetheless reasonable because the government relied upon and adhered to the strictures of the SCA.

The full implications of the Davis case still remain to be seen, but the case raises important questions about privacy interests in respect of information transmitted over the airwaves and through the internet. For example—and as several judges concurring with the court’s opinion pointed out—what differentiates a third-party internet site’s tracking of a user’s movements on its site through the use of cookies from a mobile carrier’s tracking of a user’s location? One thing that we can say for certain is that as Miami continues to develop as an incubator for technology, start-ups and innovation, the Davis case certainly will not be the last word from our courts on the intersection of privacy and technology.