Does the Fourth Amendment warrant requirement apply when the government obtains our digital information normally held by third parties? The U.S. Supreme Court will decide a case this summer that could transform privacy law in the digital era. The case, U.S. vs. Carpenter (an appeal from the 6th Circuit), began as an investigation into a series of armed robberies in the Detroit area that targeted Radio Shack and T-Mobile stores. Law enforcement determined an individual named Timothy Carpenter was the person who planned the robberies, supplied the guns and served as lookout, typically waiting in a stolen car near the robberies. Because investigators knew Carpenter communicated with the robbers and was near stores that were robbed, his location on the dates of the robberies became crucial to the investigation. They sought location data for Carpenter’s cellphone, which showed Carpenter was near each of the robberies when they were happening. Carpenter argued in court that tracking his location using his cellphone was unconstitutional. The government pushed back with a novel legal claim. It argued that it can use cellphones to track the location of anyone it wants at any time, without violating the Constitution. The Sixth Circuit Court of Appeals agreed with the government that the Fourth Amendment’s warrant requirement did not apply to cellphone tracking. Because Carpenter has no privacy or property rights in the location data that his phone transmits, and because the data does not reveal the contents of Carpenter’s phone calls, the government can obtain it without a warrant.
The Sixth Circuit’s decision appears at first to be contrary to two recent U.S. Supreme Court decisions. In U.S. vs. Riley, the Court held the police must generally have a warrant to search the cellphones of people they arrest. And in U.S. vs. Jones, the Court held the police must obtain a warrant before placing a G.P.S. device on a suspect’s car, allowing them to track his movements for 28 days.
But, the Sixth Circuit’s reasoning is why this case is so important to digital privacy. The Carpenter court determined the case based largely on the “third party doctrine,” which dictates that personal information exposed to a “third party” like a phone company, bank teller or IRS is no longer protected by the Fourth Amendment.
Why is this so important? Taking the “third party doctrine” to its logical extreme, does it also include Google searches, the websites a person visits, documents stored on clouds like Dropbox and our e-mails? Because we know most of these digital matters are stored on third-party servers are they similar to using cellphones to track a person’s location? The court in Carpenter could also make the distinction between consent and movement, i.e. Google searches are content based but one’s location is not therefore the Fourth Amendment’s requirement is not triggered.
Whatever the Court’s holding, the Carpenter case when decided in June will set the parameters for digital privacy for years to come.