The U.S. Supreme Court on Monday limited the law enforcement use of “geofence” 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 the 6-3 ruling, the U.S. top court said that “an individual has a reasonable expectation of privacy in his cell-phone location information.” According to the court, that means people have privacy rights when it comes to the location history collected by their phones, as well as the services and apps running on them.
Because of that, the court ruled that authorities need to obtain a search warrant when asking tech companies, such as Google, for the location data of their users, including when requesting historical geofence location data.
In part, the Supreme Court argued that authorities need to obtain a search warrant to get geofence location data because a user is not willingly sharing their location data to a company like Google by simply using its services. If that was the case, then the “third party doctrine,” which generally says people have no expectation of privacy when it comes to data they willingly share with others, would apply. In those cases, authorities don’t need a search warranty to obtain user data from telecom providers, for example.
Geofence warrants allow law enforcement to force tech companies to hand over information about where any of its millions or billions of users were located at a particular place in time, based on a record of their phone’s location stored in their databases. In practice, police will draw a shape over a map and ask a judge to allow them to demand that tech companies, such as Google, search their vast banks of users’ location data and tell them which of their users was there at the time of inquiry.
Critics argued that these oft-called “reverse” search warrants are unconstitutional because they are inherently overboard and include innocent people’s data.
The court seemed to agr …