Geofence warrants: US court rules warrants for the release of location data unconstitutional
So-called “geofence warrants” are “categorically” unconstitutional, a US appellate court ruled last week. Court orders demanding the release of location data have drawn criticism for years.
With a geofence warrant, law enforcement agencies in the US can demand that companies turn over information on every mobile device known to have been in a particular place at a particular time. Unlike a normal search warrant, geofence warrants do not target a specific person. For that reason civil liberties advocates say that such warrants can subject individuals to law enforcement scrutiny who have no involvement in the matter under investigation.
According to the Electronic Frontier Foundation (EFF), a civil liberties organization, Google is the key recipient of this type of court order. Many of the company’s products, like Google Maps, collect location data.
Location data used to track down suspects
The case ruled on last week concerned a 2018 armed robbery of a US Postal Service truck in Mississippi. Postal inspectors were initially unable to identify the suspects in the robbery. The inspectors applied for a geofence warrant, seeking to obtain information on smartphones whose location data showed them to have been within a certain radius of the crime scene within a one-hour timeframe.
As the Harvard Law Review has documented,, Google’s first step in responding to geofence warrants is to provide anonymized data. Law enforcement then review this data to filter out users whom they deem irrelevant to their investigation. After narrowing the field, investigators then ask for more information on individual users, like the name and email address linked to a Google account.
This was how investigators in the Mississippi case tracked down the suspects, who would eventually be convicted. In their appeal, the defendants disputed the constitutionality of the geofence warrant – and requested that the evidence obtained with the warrant not be admitted.
“Constitutionally insufficient”
In its decision the court observed that location data can be used “to follow an individual into areas normally considered some of the most private and intimate.”
The court came to the conclusion that geofence warrants are “categorically prohibited” by the Fourth Amendment to the US Constitution. The Fourth Amendment protects individuals against “unreasonable searches and seizures” by the government and specifies that search warrants cannot be issued without probable cause and without “particularly describing the place to be searched, and the persons or things to be seized.”
Because geofence warrants are not directed at a specific individual, civil liberties advocates have long argued that they are unconstitutional.
The appeals court judges stated that a company like Google that receives a geofence warrant must “search through its entire database” of location data, a search that occurs “while law enforcement officials have no idea who they are looking for.” The “quintessential problem with these warrants is that they never include a specific user to be identified, only a temporal and geographic location” – this, the court ruled, is “constitutionally insufficient.”
Decision goes into force for three US states
The online magazine TechCrunch reports that the decision issued by the US Court of Appeals for the Fifth Circuit will go into force for the states of Louisiana, Mississippi and Texas. The ruling “effectively makes the use of geofence warrants unlawful” in these states.
Nevertheless, the ruling was ultimately not in the defendants’ favor. The court found that the investigators applying for the geofence warrant in 2018 were acting in “good faith,” considering, among other factors, the “novelty of the technique” – Google had received its first geofence warrant request only two years prior, in 2016. The evidence obtained by the warrant was thus ruled to be admissible in this case.
Still, the EFF considers the decision to be an important one. “It is gratifying to see an appeals court recognize the fundamental invasions of privacy created by” geofence warrants, the organization wrote in response to the ruling. Furthermore, “it is essential that every person feels like they can simply take their cell phone out into the world without the fear that they might end up a criminal suspect.”
Related decisions
Only last year did a US appeals court review a geofence warrant for the first time. In that case, in California, the court ruled that the warrant violated the Constitution.
Last month, however, another court ruling on a separate case came to the opposite conclusion. The judges in the case based their conclusion on their finding that the defendant had “voluntarily exposed” his location data to Google.
There have been repeated reports of individuals who have been wrongly targeted by law enforcement because of geofence warrants. In 2020, for example, a man was wrongly suspected of committing a burglary – he had regularly biked past the scene of the crime while using an app to record his rides.
Meanwhile Google has announced that in the future it will only store location data locally on users’ devices. The EFF believes that this change will make it difficult or even impossible for law enforcement officials in the US to obtain location data from Google. The organization stated that it was “cautiously optimistic that this will effectively mean the end of geofence warrants.” (js)