Instead of being treated like business records, the 11th Circuit said, cellphone location data should be viewed as similar to the information at issue in U.S. v. Jones, the 2012 case in which the Supreme Court ruled that tracking a suspected drug dealer's car by attaching a GPS device to it amounts to a search under the Fourth Amendment. In fact, the appeals court said, obtaining cellphone data is even more intrusive, because cars generally remain in public places, while mobile phones go everywhere.
"The exposure of the cell site location information can convert what would otherwise be a private event into a public one," the court said. "When one's whereabouts are not public, then one may have a reasonable expectation of privacy in those whereabouts. ... 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."
The 11th Circuit is right that people reasonably expect to keep such details private, which is why the Supreme Court should reconsider the misguided notion that information shared with anyone is thereby shared with the government. But the appeals court's solution, which relies on the principle that you can't agree to disclose information when you do not realize you are disclosing it, is viable only as long as people remain ignorant of the ways in which their constant electronic companions can betray them. If you have read this column, it's too late for you.