Supreme Court Upholds Warrant Requirement in Landmark Digital Privacy Ruling

Posted on June 25, 2018

On June 22, 2018, as reported by Ars Technica, the US Supreme Court ruled in a 5-4 vote, comprised of the four liberal-leaning justices and Chief Justice John Roberts in the majority, that the government must obtain a search warrant before submitting a request to telecommunications providers for cell-site location information. The new search warrant criterion for requesting sensitive historical location data on individuals substantially raises the threshold the government must meet from its prior standard of merely demonstrating “reasonable suspicion” in an administrative warrant. 

Cell-site location information, or CSLI, is the approximate geolocation data automatically generated as a cellular device periodically registers with the nearest cell base station (also known as a cell tower) to maintain an established service connection, and which telecoms generally retain for years. In their respective majority opinions in Carpenter v. United States, more than one justice noted that their decision rested on the thorough and inescapable record of subscriber locations that cell phones make purely through normal operation–customers have no choice but to leave a digital breadcrumb trail simply by using what is to many an indispensable tool of modern life.

While the court specifically did not overturn the precedent set down in Smith v. Maryland–which establishes that account data, transaction history, and other so-called “business records” (now more commonly known collectively as metadata) intrinsically generated as part of service delivery are not subject to the Fourth Amendment probable cause warrant threshold, but to the lesser reasonable suspicion standard–it did notably carve out an exception for CSLI due to the sheer volume, pervasiveness, and sensitivity of the data generated. Effectively, this puts a hole in the previously watertight third-party doctrine set down in Smith v. Maryland and codified more formally under the Stored Communications Act by putting CSLI in another category of metadata entirely, opening the door for the imposition of Fourth Amendment protections on new classes of user data in the future.

Nathan Freed Wessler, the ACLU attorney who argued the case, underscored the modern reality of pervasive cell phone use, and the need to afford it privacy safeguards, in his statement on the case’s outcome.

“The government can no longer claim that the mere act of using technology eliminates the Fourth Amendment’s protections,” he said.

Oddly, the court ruled, without a clearly stated rationale, that the warrant requirement must be met for any request for location data spanning seven days or longer. The court also waived the need for law enforcement to secure a warrant in exigent cases with high likelihood for bodily harm, such as active shootings or kidnappings. However, the recognition that CSLI is a wholly more intrusive and saturated class of data marks a turning point in the way privacy rights are adjudicated in the 21st century. Add to this the fact that in 2017, the combined number of requests for CSLI received by AT&T and Verizon, two of the largest telecoms in the US, totaled 125,000 and this new warrant requirement extends a critical privacy protection to a vast number of users.

You can read the full story from Ars Technica here.