Fourth Circuit Appeals Court Announces It’s Going To Rethink Its Geofence Warrant Decision

This is tentatively welcome news. I mean, it can’t result in anything worse than the original decision the Fourth Circuit handed down in the Chatrie case, which said there’s nothing constitutionally wrong with searching every Google user’s location info in hopes of finding the suspect law enforcement is actually looking for. (via FourthAmendment.com)

The Appeals Court took the Supreme Court’s Carpenter decision that created a warrant requirement for obtaining cell site location info over a long period of time and took that to mean that the location info law enforcement eventually obtained in the Chatrie case wasn’t worthy of Fourth Amendment protections.

[W]e find that the government did not conduct a Fourth Amendment search when it obtained two hours’ worth of Chatrie’s location information, since he voluntarily exposed this information to Google.

So, the lynchpin here was the length of time, even if the court expressed its reservations about the use of warrants that treat everyone in Google’s location database as a criminal suspect until proven otherwise, something the dissent pointed out in the court’s July 2024 decision:

[G]eofence intrusions are even broader than the intrusion in Carpenter because there is no limit on the number of users police can include in a geofence. With CSLI, police at least had to provide a specific phone number to search, so they had to identify a criminal suspect before they could pry into his or her historical CSLI data. By stark contrast, geofence intrusions permit police to rummage through the historical data of an unlimited number of individuals, none of whom the police previously identified nor suspected of any wrongdoing. Indeed, the very point of the geofence intrusion is to identify persons whose existence was unknown to police before the search.

In the end, though, the majority thought the intrusion in Chatrie’s movements was limited enough, it didn’t raise further constitutional issues. What was never really up for discussion was the constitutionality of the geofence warrants themselves, which allow the government to treat everyone as a suspect while trying to back into the probable cause needed to target only specific suspects.

This unexpected en banc rehearing is likely due to a more recent appellate decision — one handed down by the Fifth Circuit (yeah ikr?) in August, which said geofence warrants are themselves unconstitutional. These warrants are the “general rummaging” that was directly addressed by the Fourth Amendment. Just because it’s a warrant doesn’t mean it’s a lawful warrant, especially not when they’re deployed this way:

When law enforcement submits a geofence warrant to Google, Step 1 forces the company to search through its entire database to provide a new dataset that is derived from its entire Sensorvault. In other words, law enforcement cannot obtain its requested location data unless Google searches through the entirety of its Sensorvault—all 592 million individual accounts— for all of their locations at a given point in time. Moreover, this search is occurring while law enforcement officials have no idea who they are looking for, or whether the search will even turn up a result. Indeed, the quintessential problem with these warrants is that they never include a specific user to be identified, only a temporal and geographic location where any given user may turn up post-search. That is constitutionally insufficient.

Given the timing, there can be little doubt the Fifth Circuit’s take on this issue is forcing the Fourth Circuit to reconsider its own take. The Fourth Circuit limited itself to considering whether the data eventually obtained with a warrant constituted a Fourth Amendment violation.

The Fifth Circuit’s decision, on the other hand, makes it clear the end point of vague, exploratory and, yes, “general” warrants isn’t where the constitutional conversation should start. It should actually begin at the point the government commences its investigatory work: the first geofence warrant delivered to Google that requires it to search its entire database of location data under the shaky legal theory that there’s probable cause to believe Google may possibly discover location data investigators can use to create a list of suspects.

If the Fourth Circuit rolls back its inquiry to match the Fifth Circuit’s starting point, it’s hard to see how it will arrive at the decision that geofence warrants are constitutional. If it decides the rest of this inquiry isn’t worthy of discussion, it’s just going to end up back where it started, only with a lot more wasted time and effort. At worst, nothing changes. But at best, it could generate precedent that the Supreme Court won’t be able to ignore (for better or worse).