Orin S. Kerr | 8.13.2024 5:28 AM

Once in a while there is a court ruling on the Fourth Amendment that just makes my jaw drop. The Fifth Circuit had such a ruling today, United States v. Jamarr Smith. The case creates a split with the Fourth Circuit on one important issue, and it creates another split with the Colorado Supreme Court on an even more important issue.

The new case is about the Fourth Amendment limits of geofence warrants, which are warrants to access location information for users who have opted into having Internet providers retain location history. The Fifth Circuit makes two important holdings. First, accessing any amount of geofence records is a search under an expansive reading of Carpenter v. United States. That's the issue that creates the split with the Fourth Circuit in United States v. Chatrie. As I noted just a few weeks ago, Chatrie held that accessing such records is not a search in the first place, at least if the records sought are relatively limited in scale. The Fifth Circuit expressly disagrees.

Second, and much more dramatically, the Fifth Circuit rules that because the database of geofence records is so large, and because the whole database must be scanned through to find matches, the Fourth Amendment does not allow courts to issue warrants to collect those records. In legal terms, it is impossible to have a warrant particular enough to authorize the surveillance. The government can't gather these kinds of online records at all, in other words, even with a warrant based on probable cause. This holding conflicts with a recent ruling of the Colorado Supreme Court, People v. Seymour, and more broadly raises questions of whether any digital warrants for online contents are constitutional.

There's obviously a lot going on in this new decision. Because I have blogged about the search issue several times before, including just last month, I want to focus this post instead on the second ruling—that geofence warrants are not permitted, even with probable cause. I think this ruling is wrong, and that it's very important for it to be overturned. This post explains why.

I. The Legal Context

First, some context. When the government obtains a geofence warrant, the provider is ordered to provide data matching the geofence. The warrant will call for the provider to hand over records made in a particular window of time and that recorded locations in a particular physical area. The provider has a database consisting of location records of the accounts that opted into the service, and the provider—here, Google—searches through the database looking for a match with the records sought in the warrant. Google calls this "Step 1" of its geofence warrant process. If Google finds matches, it then goes through further steps that ultimately gives the government records that are responsive to the warrant.

Warrants have to be particular, and particularity requires two things. First, the place to be searched must be particular. For example, the government can't get a warrant to search an entire city block, or to search the entirety of an apartment building with lots of independent units. The place that is searched through has to be smaller than that, like a single business or (more often) a single house. Second, particularity requires a particular description of the thing to be seized. The government can only take the evidence or contraband that is evidence of the crime.

Most discussions of particularity are about the particularity of the things to be seized. Prior discussions of particularity for geofence warrants have focused on that. The issue has been, how broad can the warrant can be in terms of how much time and space the warrant can cover? A geofence warrant orders the provider to hand over records that were of users in a particular area for a particular span of time. A warrant might cover, say, within a mile of where the crime occurred, for, say, the 30 minutes before the crime occurred and up to 30 minutes after it. But that kind of particularity is about how broad the records can be that the government gets.

The issue in Smith is about the first kind of particularity—the place to be searched.

II. The Warrant Ruling

Smith rules that the database that Google has created, through which Google looks for matches with the data described in the warrant, is just too big to search. Google combines all of its location records from all of its users worldwide into a single database, covering an estimated 592 million people, that it calls Sensorvault. When Google queries that Sensorvault database, the Fifth Circuit holds, it is scanning through a "place" too big for the Fourth Amendment to allow.

Here's the entirety of the court's above-the-line analysis on this issue, with italics in the main text in the original:

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........

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