Supreme Court rules geofence warrants require Fourth Amendment privacy safeguards

The US supreme court decided that law enforcement must follow constitutional privacy rules when deploying geofence warrants to gather smartphone location information, classifying the practice as a fourth amendment search.

The court finds reasonable expectation of privacy in location records. Justice Elena Kagan authored the majority opinion for the 6-3 ruling in Chatrie v US. The decision determined that people hold a "reasonable expectation of privacy" in their cell phone location records, "even though for only a limited time, and from a third-party tech company," as Kagan put it.

She added that officers violate protected interests by compelling production of the data. The justices turned aside the government's position that brief collection of such details falls outside fourth amendment coverage.

Geofence warrants enable broad data collection near crime scenes. The orders direct technology firms to surrender location details from anyone present inside a digital perimeter around an offense during a set window. They do not limit requests to identified suspects, prompting objections that the method functions as an unconstitutional dragnet.

This dispute arose from an armed bank robbery in Richmond, Virginia, where the perpetrator escaped with $195,000. Officers identified Okello Chatrie by obtaining geofence records after he had activated Google's voluntary "location history" setting, which logged his position every few minutes. He later pleaded guilty and received a 12-year prison term.

Lower court ruling is thrown out and case remanded. The supreme court vacated the earlier decision that had upheld the evidence against Chatrie. According to SCOTUSblog, justices sent the matter back for additional fourth amendment review of whether the warrant satisfied requirements for particularity and probable cause.

The prevailing opinion labeled the government's claim that users voluntarily generate location histories as "meritless." It stressed that ordinary smartphone activity does not equate to consenting to share sensitive details with authorities or corporations.

Court highlights how location services are integral to smartphone use. The writers observed that users carry the devices primarily to access their apps and features, many of which depend on location information for personalization. The ruling faulted Google's repeated prompts to activate the service, which caution that phones "will not work correctly" otherwise while omitting details on recording frequency, precision and potential disclosure to law enforcement.

Justice Sonia Sotomayor observed that "even short-term monitoring" of movements can reveal extensive information about a person's familial, political, professional, religious and sexual associations. The outcome strengthens arguments from those who consider the warrants excessively sweeping and serves as a key examination of digital-age privacy standards.