Privacy Unfenced

The U.S. Supreme Court will soon consider whether the conviction of an alleged bank robber based on his cell phone location data was constitutional. Authorities located the defendant using a geofence, which establishes a virtual perimeter around a specific geographic location. After obtaining a warrant for the defendant’s location data from Google, police searched the defendant’s house and found incriminating notes and a nine millimeter pistol. At trial, the defendant tried to withhold the location data from the jury but a court denied his request, convicting and sentencing him to nearly twelve years in prison. The defendant now argues that the search violated his Fourth Amendment protection against unreasonable searches.

Companies use geofences to provide targeted ads to their users. But since federal authorities obtained its first geofence search warrant in 2016, law enforcement has sought this information in a growing number of criminal investigations.

Geofence warrants raise two related legal issues: Whether the collection and review of geofence data constitute a “search” under the Fourth Amendment, and, if so, whether the warrant procedure is sufficiently protective of an individual’s Fourth Amendment right to be free from unreasonable law enforcement searches. Courts disagree on whether law enforcement geofence warrants are even a search. They also diverge on the question of whether warrants do enough to protect an individual’s privacy.

These legal disagreements may soon be resolved. Commentators expect the Supreme Court to weigh in on the constitutionality of geofence warrants when it hears the bank robbery appeal this summer.

Geofences collect sensitive data, raising privacy concerns. Their proliferation leads many legal experts to call for the regulation of mass surveillance tools in general. Tech companies currently self-regulate the collection and organization of geofence data. Google recently announced that it would phase out the internal database containing user geolocation data. Though the move will make it more difficult for law enforcement to seek geofence data moving forward, experts warn that it may not guard against warrants seeking data previously stored in the database.

In addition to broader privacy concerns, reproductive rights experts warn that geofence data could be used to harass or even prosecute abortion seekers. In states where abortion is criminalized, experts note that prosecutors could use geofence data against alleged abortion recipients. Two states currently prohibit corporations from establishing a geofence near a health care facility, though there is no federal prohibition on the practice.

The current lack of federal regulation of geofence data collection, and the proliferation of geofence warrants generates a robust debate about the nature of privacy in the digital age. But critics say that the breadth of geofence warrants will invariably lead to the investigation and prosecution of innocent people. For example, an Arizona man sued Google after being arrested for a murder committed by a man to whom he lent his phone.

In this week’s Saturday Seminar, scholars discuss the legality and potential regulation of geofence warrants.

• In a recent article in the Utah Law Review, practitioner Shelby Stender argues that geofence warrants lack are unconstitutional under the Fourth Amendment. Stender explains that police increasingly use these geolocation data searches to identify not only criminal suspects but also protesters, abortion seekers, and many innocent individuals. Stender contends that existing judicial remedies are inconsequential, as the good-faith exception to the Fourth Amendment prohibition against the use of illegally obtained evidence at trial allows courts to admit such evidence when officers relied on a judge-approved warrant. With courts offering little protection for sensitive location data and requests for geofence warrants surging nationwide, Stender concludes that only a statutory ban on geofence warrants could curb abuses of this practice.
• In an article in the Cardozo International & Comparative Law Review, practitioner Aaron Bengart warns that law enforcement’s growing reliance on geofence warrants raises serious privacy concerns. Bengart describes how major technology companies collect vast amounts of location history data from cell phones—tracking users roughly every two minutes—and that police increasingly seek geofence warrants to obtain this information. These warrants allow officers to request data on every device located within a specified geographic area, including many people unconnected to the underlying investigation, Bengart notes. Bengart advocates proposed legislation, including New York’s Reverse Location Search Prohibition Act, which would bar courts from issuing geofence warrants and require suppressing any evidence obtained through them.
• General geofence warrants not specifically tailored to uncover evidence of a particular crime in a particular place violate the Fourth Amendment, argues Mary Fan of the University of Washington School of Law in an article. Fan explains that, to be constitutional, a geofence warrant must have “digital probable cause,” meaning that such warrants can only be granted when it is likely that a database controlled by a corporation has evidence of an existing crime. Geofence warrants do not have to target a particular suspect to be constitutional, Fan contends. Fan advocates updating the law of search warrants to account for the reality that information collected by tech companies can be used as incriminating evidence.
• Geofence warrants are not searches under the Fourth Amendment, argues Jordan Wallace-Wolf of the University of Arkansas at Little Rock William H. Bowen School of Law in an article. Wallace-Wolf contrasts the Supreme Court case holding that the long-term digital tracking of an individual is a search with a subsequent lower court case holding that geofence warrants do not violate individual privacy expectations. He explains that, unlike the long-tern digital tracking of an individual, geofences do not target a particular suspect. Wallace-Wolf contends that the latter decision places geofence warrants outside of the reach of the Fourth Amendment. He anticipates that future defendants will not be able to suppress evidence produced from geofence warrants.
• Barbara Bathke of Tulane University School of Law examines the considerations that geofence warrants pose for courts in an article in the Tulane Journal of Technology and Intellectual Property. The extensive scope of the data collected from geofence warrants cannot be understated, Bathke contends, and the high degree of precision in location tracking tools implicate significant privacy concerns. She explains that geofence warrants do not require law enforcement to specify a user or device, and likely include data of innocent individuals with no connection to the alleged crime. Bathke notes that courts have been reluctant to rule on the constitutionality of geofence warrants, but that judges are skeptical that such warrants are sufficiently particularized to meet Fourth Amendment requirements.
• Geofence warrants fit within the reasonable expectation of privacy doctrine as it relates to technology, contends Sahara Damon of The George Washington University Law School in an article. If geofence warrants are subject to a reasonable expectation of privacy, she continues, then they are also subject to Fourth Amendment protections, which would limit the ability of law enforcement officers to gather vast amounts of revealing data. Damon highlights a 2018 Supreme Court case in which the Court held that location history data searches are deep invasions of privacy that implicate the Fourth Amendment. Damon concludes that geofence warrants are unconstitutional and advocates the implementation of guidelines to that geofence warrants comply with the Fourth Amendment.