The US Supreme Court has strengthened digital privacy protections by ruling that law enforcement conducts a Fourth Amendment search when it obtains historical location information generated by a person’s smartphone.
The 6-3 decision in Chatrie v. United States extends constitutional protection beyond the cell-tower records considered in the Court’s landmark 2018 Carpenter ruling. It covers detailed location history collected through smartphone applications and stored by technology companies, even when police request only a short period of data.
The ruling does not make phone-location evidence unavailable to investigators. It means the government must treat access to that information as a constitutionally significant search and ordinarily justify it through a properly issued warrant.
For smartphone users, the central message is clear: using an application that collects location data does not automatically give the government unrestricted access to that digital record.
The Case Began With a Virginia Bank Robbery
The dispute arose from the 2019 robbery of a credit union near Richmond, Virginia.
Investigators obtained a geofence warrant requiring Google to identify devices detected near the bank around the time of the crime. Unlike a traditional warrant aimed at a known suspect, a geofence request begins with a place and time and asks a technology company to identify devices found within that area.
Google initially supplied anonymized information for accounts detected within roughly 150 meters of the credit union during a one-hour period. Investigators then requested broader movement data for selected accounts before obtaining identifying subscriber information. One of those accounts was connected to Okello Chatrie.
Police later searched Chatrie’s home and recovered nearly $100,000, including cash linked to the robbery. He pleaded guilty and received a prison sentence of almost 12 years, but challenged the location-data search as unconstitutional. The full procedural history appears in the Supreme Court’s official Chatrie opinion.
Location History Is More Revealing Than a Simple Map Pin
The Court’s reasoning focused on the extraordinary detail contained in modern smartphone location records.
Location history can reveal when someone visited a medical clinic, religious institution, political meeting, romantic partner, workplace or private residence. When viewed collectively, those points can reconstruct daily routines and personal associations with remarkable precision.
The Court explained that smartphone databases allow authorities to examine past movements retrospectively and at scale. Investigators no longer need to follow a person physically or know whom they are searching for before beginning surveillance. A database can effectively allow police to look backward in time.
Justice Elena Kagan’s opinion compared location history with private materials such as emails, photographs, calendars and personal documents. Even when those items are stored on a company’s servers, users may reasonably regard them as private and protected from unrestricted government examination.
That conclusion reflects a continuing change in Fourth Amendment law. Privacy is no longer determined only by whether information physically sits inside a home or belongs to a third-party company. Courts must also consider how much intimate information a modern technology can reveal.
Protection Applies Even to Short Periods of Tracking
One of the ruling’s most important conclusions concerns duration.
The government argued that the approximately two hours of location history obtained in Chatrie’s case was too limited to constitute a Fourth Amendment search. The earlier Carpenter v. United States decision had involved at least seven days of cell-site location records, leaving uncertainty about shorter requests.
The Supreme Court rejected the idea that law enforcement receives a warrant-free period for short-term location tracking.
Its opinion stated that even a brief record may expose sensitive details about a person’s family, professional life, religion, politics or private relationships. Constitutional protection does not begin only after investigators collect a particular number of hours or location points.
The decision therefore removes a major ambiguity left by Carpenter. According to a detailed Reuters legal analysis of the ruling, historical smartphone-location information receives protection regardless of whether authorities request two hours or several days.
Opting Into an App Does Not Eliminate Privacy
The government also relied on the third-party doctrine.
Under traditional versions of that doctrine, people generally have a reduced expectation of privacy in information voluntarily shared with another company, such as telephone numbers dialled or ordinary banking records.
Prosecutors argued that Chatrie had chosen to enable Google’s Location History feature and had therefore voluntarily provided the information to Google.
The Court rejected that reasoning.
Modern smartphones require users to interact continuously with applications and digital services. Approving a location permission or activating a feature does not necessarily mean the person knowingly agrees that the government may later obtain a detailed record of their movements.
The majority noted that technology companies frequently prompt users to activate location features without clearly explaining how frequently information will be collected, how precise it may become or how authorities could later request it.
The Court therefore held that ordinary smartphone activity should not be treated as complete surrender of constitutional privacy. The Associated Press account of the decision explains that users retain a reasonable expectation of privacy even after opting into a company’s location service.
The Ruling Builds on Carpenter v. United States
The Supreme Court’s digital-location doctrine began taking clearer shape in 2018 with Carpenter v. United States.
In that case, investigators obtained 12,898 cell-site location points covering Timothy Carpenter’s movements over 127 days. They used a lower-level court order rather than a probable-cause warrant.
The Court ruled that acquiring those records amounted to a Fourth Amendment search. It recognized that mobile phones generate a detailed chronicle of their users’ physical movements and that carrying a phone is effectively unavoidable in modern life. The original Carpenter opinion remains the foundation for current location-privacy law.
However, Carpenter was deliberately narrow. It dealt with cell-site information maintained by wireless carriers and did not fully resolve the status of shorter tracking periods, application-generated location data or reverse-location warrants.
Chatrie expands that framework. Constitutional protection now reaches historical location information created through smartphone applications, not only records generated when a phone connects to cellular towers.
The Court Did Not Ban Geofence Warrants
The decision is a major privacy ruling, but it does not declare every geofence warrant unconstitutional.
The Supreme Court answered the threshold question: obtaining smartphone location history is a Fourth Amendment search.
It did not finally decide whether the specific warrant used against Chatrie satisfied the amendment’s requirements. The justices sent that issue back to the lower courts for further analysis.
That distinction matters because the Fourth Amendment does not prohibit every government search. It prohibits unreasonable searches and generally requires warrants to be based on probable cause and to describe with sufficient particularity what may be searched or seized.
Geofence warrants create a difficult particularity problem because they may collect information about many innocent people before police identify a suspect. A request covering a bank, surrounding businesses, nearby homes or a place of worship can expose the movements of individuals with no connection to the investigated crime.
Future cases will have to determine how narrowly such warrants must be written, how much discretion investigators may receive and whether certain reverse-location searches resemble the general warrants the Fourth Amendment was designed to prevent.
What the Decision Means for Technology Companies
Technology companies that retain smartphone-generated location data must now evaluate government requests more carefully.
A subpoena or lower-level disclosure order may not be enough when the requested records reveal a person’s historical movements. Providers may need to demand a warrant, challenge an overly broad request or seek clarification before releasing information.
The ruling applies most directly to smartphone-location records, but its reasoning could influence disputes involving other sensitive digital information. Fitness records, connected-vehicle data, advertising identifiers and application activity may sometimes reveal where a person has been even when they are not formally labelled “Location History.”
The Court did not decide those future questions. However, its emphasis on revealing, involuntarily generated smartphone data provides privacy advocates with a stronger foundation for challenging other forms of digital surveillance.
What It Means for Ordinary Phone Users
The decision does not prevent applications from collecting location data under their own privacy policies. It also does not stop companies from using that information for navigation, recommendations, advertising or other disclosed services.
The ruling concerns government access and constitutional procedure.
Police can still obtain relevant records when they establish probable cause and secure a lawful warrant. Emergency exceptions may also apply in situations involving imminent threats, missing people or immediate danger.
Users should still review application permissions because constitutional protection is not the same as complete data privacy. Companies may retain extensive location records, and those records may be exposed through security breaches, commercial sharing practices or civil legal demands outside a criminal investigation.
Nevertheless, the judgment establishes an important boundary. A smartphone may constantly create a record of its owner’s movements, but that technological reality does not place the record outside the Fourth Amendment.
A Major Victory for Digital Privacy
Chatrie v. United States confirms that constitutional protections must adapt to technologies capable of revealing far more than traditional surveillance methods.
The government cannot avoid Fourth Amendment scrutiny merely because private companies store the information, the user activated a location-based feature or investigators requested only a short window of movement.
The ruling does not end geofence investigations, and it does not resolve every dispute involving digital tracking. It does establish that historical phone-location data is private enough to trigger constitutional protection.
That principle will shape policing, technology-company disclosure practices and digital privacy litigation for years to come.
