In a major win for privacy, the Supreme Court ruled that geofencing orders are protected by privacy rights

The U.S. Supreme Court on Monday limited law enforcement’s use of “geofencing” search warrants in a major legal ruling that is likely to have broad ramifications for privacy rights and law enforcement across the United States.

In ruling 6-3the U.S. Supreme Court said that “an individual has a reasonable expectation of privacy in his or her cell phone location information.” According to the court, this means that people have privacy rights when it comes to location history collected by their phones, as well as the services and apps that run on them.

For this reason, the court ruled that authorities need to obtain a search warrant when asking technology companies, such as Google, about the location data of their users, including when requesting historical geo-location data.

In part, the Supreme Court argued that authorities needed to obtain a search warrant to obtain geolocation data because a user does not willingly share their location data with a company like Google simply by using its services. If so, then “Third party doctrine“, which generally states that people have no expectations of privacy when it comes to data they willingly share with others, will apply. In those cases, authorities do not need to warrant research to obtain user data from telecommunications providers, for example.

Geofence’s orders allow law enforcement to force tech companies to hand over information about where millions or billions of their users are in a particular place at a given time, based on their phone’s location history stored in their databases. In practice, police will draw a shape on a map and ask a judge to allow them to ask tech companies, such as Google, to dig into their huge collections of user location data and tell them which users were there at the time of the investigation.

Critics have argued that these “reverse” search warrants are unconstitutional because they are inherently excessive and include data on innocent people.

The court appeared to agree, but stopped short of banning the use of geolocation warrants altogether, allowing police to narrow the scope of data requests when seeking a search warrant.

In other words, the Supreme Court simply ruled that the Fourth Amendment, which protects against unreasonable searches and seizures and effectively protects privacy rights, applies to location data that companies like Google collect from their users’ cell phones. The decision does not prevent law enforcement from obtaining historical cellphone location data, but simply rules that authorities need to obtain a search warrant when requesting geofence location information and showing that there is probable cause that the target committed a crime.

The decision is based on a case brought by Chatri v. United StatesWho accused the government of using evidence during his trial for bank robbery that had been collected under an unconstitutional search warrant. Okello-Shatri’s lawyers argued that geofencing orders allow investigators to “search first and raise suspicions later,” flouting long-standing standards for how government authorities are required to search for or seize data from companies.

Authorities typically must establish “probable cause” linking a person to a crime to justify a search warrant, while critics argue that geofence warrants work in reverse.

supreme court He took up the case After several legal cases involving geofence orders, including the Chatri case, it divided courts across the United States, including at the appellate level.

It is not immediately clear how the ruling will affect previous court cases. A Justice Department spokesman did not respond to a request for comment.

The ruling was not expected to change Chattri’s ruling in his case as previous courts had ruled that evidence obtained from the geolocation warrant had been collected in good faith. Chatri’s lawyers did not respond to a request for comment from TechCrunch.

The Supreme Court ruled that it was now up to the Court of Appeals to decide whether the search warrant sought in the Chatri case showed probable cause and was therefore valid.

Some companies that were repeatedly targeted by requests for location data, such as Google, began storing users’ location data on their devices rather than on their servers to stop handing over user data, prompting investigators to go to the users themselves. Other companies that store location data, such as Microsoft, Uber, and Yahoo, also receive geolocation commands on a regular basis.