Whether the warrantless seizure and search of historical cell phone records revealing the location and movements of a cell phone user over the course of 127 days is permitted by the Fourth Amendment.
This is a big deal. Right now, federal statute requires only reasonable suspicion for police to get records showing a cell phone’s location over time. This case asks the Court to decide whether reasonable suspicion is enough, or whether the government must instead show probable cause and get a warrant before it can learn where your phone (and therefore, most likely, you) have been for the past few weeks, or months, or longer. (Our state supreme court has addressed similar issues but failed to come up with a majority rule. Now they won’t have to try again.)
Per the petition, government cell-phone tracking is not a rare occurrence–for example, a single carrier, AT&T, received 75,302 law enforcement requests for location information in a single year. Obviously, being able to place a particular person in a particular vicinity at a particular time is of great value to police and prosecutors. It also has obvious potential for abuse. To know a person’s location over time is to know a great deal about that person’s ostensibly private life. The utter pervasiveness of cell phones will likely mean that the Court can’t simply rely on modest extensions or modifications of existing precedent to reach a sensible set of rules–it will have to address deeper questions about the privacy, that the Fourth Amendment is supposed to ensure.
Which is why this case is about more than the (already important) specific question presented. We can’t say it better than Orin Kerr, who has done a great deal of work in this area, and we won’t try. Read his essential post at the Volokh Conspiracy and stay tuned for what should be a fascinating (and momentous) decision.