The United States Supreme Court has ruled in Carpenter v. U.S. that some cellular phone location data is covered by the Fourth Amendment.
Timothy Ivory Carpenter was convicted of a series of armed robberies in Ohio and Michigan. He was convicted and sentenced to almost 116 years in prison based on cell-site records from his cell phone provider that police used to place him in the vicinity of the crimes. Carpenter argued the police obtained the records illegally, without a warrant, and so they couldn’t be used against him. The Supreme Court agreed.
The “third-party doctrine” covers most information other people have about you, that you have given them. The Supreme Court has ruled that if you give information to another, you can no longer expect that information to be private. In this case that would mean, since Mr. Carpenter voluntarily chose to use this device which reported his location to the carrier, he did not have a legally enforceable expectation of privacy in those records.
The rule is often applied to deposit types and amounts with financial institutions, for instance, but the issue has never been ruled on with cell location data. Many headlines published early after the decision declared that the police now need a warrant to track your phone. Well, maybe.
No Bright Lines
As with many other big cases this term, the 5-4 decision here was narrowly drawn. That means to many of us speculators outside the chambers that the majorities are tenuous at best. No bright line rule was drawn in this case, and it’s simply not honest to claim this data is protected by the Fourth Amendment, without discussing the many exceptions to that claim.
Amy Howe of SCOTUSblog talks about this aspect of Chief Justice Roberts’ opinion:
He acknowledged that law-enforcement officials might sometimes still be able to obtain cell-site location records without a warrant – for example, to deal with emergencies such as “bomb threats, active shootings, and child abductions.” And in a footnote, he also left open the possibility that law-enforcement officials might not need a warrant to obtain cell-site location records for a shorter period of time than the seven days at issue in Carpenter’s case – which might allow them to get information about where someone was on the day of a crime, for example.
How is a police force or court to know, in light of this language, where to draw the line? Sadly, no footnote from the Chief Justice of the United States settles that question. Only more court cases will.