The Supreme Court decided today in Carpenter v. United States that the government’s acquisition of cellphone records to discover the historical location of a defendant can be a Fourth Amendment search. The decision should help prevent low-value “fishing expeditions” by law enforcement of Americans’ cellphone records.
The case comes at a time when domestic surveillance by intelligence agencies is under scrutiny, and smartphone and internet records are playing a greater role in law enforcement investigations. Today, technological advancements mean we each turn over tremendous amounts of personal data to third parties simply with routine use of digital services. New services that transmit data to the cloud, like “smart homes,” voice-activated devices, and shared documents, offer law enforcement a treasure trove of personal records that, many courts have held, does not require a warrant to collect.
The Carpenter decision gives more protection to the location information that Americans routinely turn over with their connected devices and gives guidance to lower courts on how to apply the Fourth Amendment’s protection against unreasonable searches.