Tracking devices have long been staples in the government’s investigatory toolkit. But law enforcement’s tracking device of choice is now the suspect’s own cell phone. In the burgeoning litigation after Carpenter v. United States over protections for prospective cell phone location information, the Tracking Device Statute (TDS)—enacted as a part of the 1986 Electronic Communications Privacy Act (ECPA)—has been overlooked as an avenue to regulate law enforcement usage of cell phones as investigative tools.

This Note first argues that cell phones are properly classified as tracking devices under ECPA and prospective location information can only be obtained under the provisions of the TDS. This Note then explains why the only federal appellate decision squarely addressing the issue, the First Circuit’s 2019 decision in United States v. Ackies, is wrongly decided. This Note concludes with a consideration of other technologies, applying the TDS to wearable health monitors, computers, and other devices in the smart home.