U.S. Supreme Court Holds Expectation of Privacy in Cell Phone Geolocation Data

Stacked3Here is a recent Daily Record column. My past Daily Record articles can be accessed here.


Smartphones have become central to the lives of most Americans. We count on our phones to keep us connected to the world. Because our phones handle so many pivotal functions for us, we’ve become increasingly reliant on them. They’ve have become so much a part of our day-to-day lives that, if you’re anything like me, you feel a bit lost when you realize you’ve misplaced your phone.

Our phones are important to us because of their utility, in part because they instantaneously provide us with incredibly relevant and up-to-date data and information about the world around us. Of course, much of that usefulness is derived from the massive amounts of personal data collected by our phones and the apps running on them. That data serves as the basis for a more personalized and functional experience.

Unfortunately, the very same data the makes our phones so valuable to us can also be used against us, sometimes by criminals, and other times by law enforcement. Last month, the United States Supreme Court considered the latter situation in Carpenter v. U.S., No. 16-402, 585 U.S. ____ (2018).  At issue was whether governmental access to historical geolocation cell phone data in order to ascertain a user’s movements constitutes a search.

Importantly, at the outset, the Court explained that careful vigilance was required when applying Fourth Amendment jurisprudence to the technological advancements that provide law enforcement with increasingly invasive access to personal information: “We have kept…Founding-era understandings in mind when applying the Fourth Amendment to innovations in surveillance tools. As technology has enhanced the Government’s capacity to encroach upon areas normally guarded from inquisitive eyes, this Court has sought to ‘assure preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.’”

The Court then turned to an examination of the specific type of information at issue in the case at hand: cell phone geolocation data. The Court noted that it is nearly impossible for users to prevent the collection and storage of their phone’s geolocation data: “Apart from disconnecting the phone from the network, there is no way to avoid leaving behind a trail of location data. As a result, in no meaningful sense does the user voluntarily “assume the risk” of turning over a comprehensive dossier of his physical movements.”

Next the Court considered whether stored geolocation data was protected by the Fourth Amendment and concluded the it was: “Given the unique nature of cell phone location records, the fact that the information is held by a third party does not by itself overcome the user’s claim to Fourth Amendment protection. Whether the Government employs its own surveillance technology as in Jones or leverages the technology of a wireless carrier, we hold that an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured through (cell phone location information).”

The Court explained that because there is an expectation of privacy in a phone’s geolocation data stored on third party servers, a warrant is required in order for the government to access it: “The Government’s acquisition of the cell-site records was a search within the meaning of the Fourth Amendment…Having found that the acquisition of Carpenter’s CSLI was a search, we also conclude that the Government must generally obtain a warrant supported by probable cause before acquiring such records.”

Of note, the Court clarified that although a warrant is generally required to access stored geolocation data, said requirement was inapplicable in the face of exigent circumstances.

Finally, the Court wisely recognized its duty to “ensure that the ‘progress of science’ does not erode Fourth Amendment protections.” Given the rapid rate of technological advancement that we’ve seen over the past decade and the fact the pace of change will only increase exponentially in the years to come, this acknowledgement was reassuring.

Technology provides incredible benefits, but privacy issues abound. Protections from unfettered governmental access to the increasingly personal data collected by our phones are needed now more than ever. The Court’s holding in this case strikes the right balance and provides much-needed guidance in the midst of a turbulent and increasingly invasive technological landscape.

Nicole Black is a Rochester, New York attorney, author, journalist, and the Legal Technology Evangelist at MyCase  law practice management software. She is the author of the ABA book Cloud Computing for Lawyers, co-authors the ABA book Social Media for Lawyers: the Next Frontier, and co-authors Criminal Law in New York, a Thomson Reuters treatise. She writes legal technology columns for Above the Law and ABA Journal and speaks regularly at conferences regarding the intersection of law and technology. She can be reached at [email protected]