Breaking Down Chatrie v. US, the Supreme Court’s Landmark Fourth Amendment Decision
Last week, the Supreme Court issued its first major Fourth Amendment case in six years: Chatrie v. United States. Chatrie is a massive victory for digital privacy. It holds that geofence searches, which use cellphone data to track all cellphone users in a certain area at a certain time, are Fourth Amendment searches requiring probable cause and a warrant. It sharply limits the “third-party doctrine,” which held that data disclosed to a third party service provider lost all Fourth Amendment protection and could be obtained by the government without a warrant or cause. More than that, Chatrie definitively establishes that Fourth Amendment law in the digital era will be appropriate to that era, and not anchored to traditional property concepts or distant analogies to non-digital contexts. The future of Fourth Amendment law has never been brighter.
The Chatrie case involved the investigation of a bank robbery. On May 20, 2019, a man wearing a fisherman’s hat and a traffic vest robbed a bank in Midlothian, Virginia. Witnesses and surveillance cameras observed him using a cellphone. Police officers served Google with a geofence warrant, and obtained information on several cellphones in the area at the time of the robbery. These included Okello Chatrie’s phone, and he was eventually identified as the culprit. Chatrie challenged the validity of the geofence warrant, arguing that it was unconstitutionally overbroad. A Fourth Circuit panel held that geofence searches were not covered by the Fourth Amendment and did not require a warrant in the first place. The en banc Fourth Circuit split 7-7 on the issue.
The Supreme Court’s decision in Chatrie’s favor was 6-3. Justice Kagan wrote the majority, joined by Chief Justice Roberts and Justices Sotomayor, Kavanaugh, and Jackson, with Justice Gorsuch concurring in the result. There were two big questions in Chatrie. First, is geofence surveillance a Fourth Amendment “search” even though it only collects a few hours’ worth of a suspect’s location data, as opposed to the seven days found to be a search in 2018’s Carpenter v. United States? Second, is geofence surveillance a Fourth Amendment “search” even though Chatrie clicked “yes” on a permission screen when setting up his cellphone, allowing Google to collect his location data with his apparent consent? The Supreme Court answered yes to both of these questions, and in doing so substantially expanded the scope of the Fourth Amendment in the digital world.
The Court acknowledged that Chatrie was only tracked for a few hours. But it ruled that this did not preclude Fourth Amendment protection, for several reasons. Importantly, the surveillance in this case was retrospective, meaning that the government could obtain data about anyone at any previous time it chooses. Although the actual surveillance only covered a few hours, the time period of potential surveillance was “boundless.” In Justice Kagan’s elegant phrasing:
The sweep of the official invasion is not made less because the government, with the benefit of hindsight, can pinpoint exactly which few hours of movements it wants to review. That feature of accessing location data is, indeed, more a practical benefit to the government than a limit on its intrusive powers.
Moreover, in the geofence context, even short-term monitoring can reveal sensitive information, because the government can precisely track those who travel to “the psychiatrist, the plastic surgeon, the abortion clinic, the AIDS treatment center, the strip club, the criminal defense attorney, [or] the by-the-hour motel.” The Court also emphasized that geofence searches could reveal when people and their cellphones were inside private residences; the Court has previously held that tracking devices that go inside the home violate the Fourth Amendment.
The Court went even further, critiquing the very idea of making Fourth Amendment law turn on exactly how long a given surveillance practice extends. It likewise pointed, in a footnote, to the line drawing issues that might arise from such an approach. The Court may have been a bit overzealous in this part of the opinion. As I argue here, it makes sense to ignore how long the government tracks someone’s location when the surveillance is retrospective, because retrospective surveillance subjects people’s entire lives to monitoring. But the idea that the Court should never take duration into account is misguided and likely to harm privacy in future cases where a few moments of observation is clearly lawful (a police officer taking a photo of a house from a public sidewalk) but a longer period of observation may not be (police setting up a sophisticated hidden camera on a utility pole to monitor a house and yard for months or years at a time). Hopefully the Court can reexamine its short but unfortunate detour in a future case, when the importance of duration becomes clearer.
Likely the most important aspect of Chatrie is the sharp limits it places on the third-party doctrine, and its rejection of the government’s claim that Chatrie waived his Fourth Amendment rights by voluntarily disclosing his location data to Google. In Carpenter, the Court declined to apply the third-party doctrine because cell phone data were automatically and unavoidably shared with cell phone providers whenever a cell phone was turned on. The Chatrie Court extended Carpenter to situations where users affirmatively chose to use a cellphone app, even if they gave permission for the app to collect their data. The Court did so for a common-sense reason: cellphone users are obviously going to use popular apps like Google Maps and are generally going to give those apps their data because that’s how apps work. Using apps is basically the reason why people have smartphones. The Court rejected an “app-by-app, feature-by-feature method of granting Fourth Amendment protection.” Rather, it concluded that smartphone users retain Fourth Amendment rights in their data when they use apps on their smartphones. In a world where “[p]retty much everything a person does on a smartphone requires some kind of opt-in,” it would be inappropriate to withhold constitutional protections for sensitive data just because a user discloses their information to a service provider. So long as cellphone use, or the use of any technology, is a part of life in the digital era, the Court will no longer penalize its users by stripping away their Fourth Amendment rights.
This portion of the opinion is momentous, a sea change in how the Court assesses voluntary disclosure. Going forward, if a person is engaged in a common activity that they could in theory avoid and which results in the disclosure of their information to a third party, they will nonetheless not be deemed to have voluntarily exposed their information. Not only would this cover a wide variety of activity on a cellphone, but also a vast swath of internet activity, and likely also non-digital activity like failing to put up a privacy fence around one’s home or walking on public sidewalks pervasively monitored by facial recognition cameras. The third-party doctrine is, if not entirely dead, on life support. It is increasingly confined to a handful of old cases decided prior to the digital era and preserved largely via stare decisis. The Court, in other words, is discarding old doctrines no longer suitable to the modern world and preserving meaningful Fourth Amendment protections in the digital era.
The Court also correctly noted that Google’s permission screen did not inform users about virtually any aspect of its data collection and use. And the Court made clear that it did not care if only a relatively small portion of users disclosed their data to a given app; those users that did would still retain a Fourth Amendment right in the data.
Finally, the Court remanded the case to the Fourth Circuit to rule on whether the warrant obtained in the case was supported by probable cause and sufficiently particularized. (Justice Jackson wrote a concurrence arguing that it was not particularized enough.) The Fourth Circuit panel had not reached that issue, finding instead that there was no search and therefore no constitutional limits on geofence searches in the first place. It is worth noting that the panel’s endorsement of a maximalist power to surveil people via Google data backfired, and not only because its holding was ultimately reversed by the Supreme Court. Following oral arguments before the Fourth Circuit panel, Google almost immediately changed how it stores geofence data, essentially ending Google geofence searches and depriving police of a valuable investigative tool they could have used by obtaining a warrant. The government’s attempt to secure an unfettered, easily abused power to surveil cellphone users ended up making it more difficult to carry out valid law enforcement functions.
The concurrences and dissents were, in their own way, almost as interesting as the majority opinion. Justice Gorsuch wrote separately to argue that the Court should discard the longstanding “reasonable expectation of privacy” test and instead resolve the case on the basis that Chatrie had a property right in his Google Location history. Gorsuch contended that Chatrie owned the data, compiled by Google and stored on Google’s servers, because he could access, export, or delete it. He also pointed to positive law as a source of property rights in Location History, noting that Virginia’s Computer Crimes Act refers to computer data as a form of property under the statute. It is possible that Chatrie’s Location History data was literally his property, but there is no authority on point to indicate that it is. As the majority pointed out, the Court has been applying the “reasonable expectation of privacy” test for roughly sixty years. That body of law is far more developed than the law of property rights in obscure forms of digital data that most users are unaware exists and which is generally not the subject of trespass litigation.
Justice Alito’s dissent had two very different parts. He lodged a reasonable disagreement, noting that the surveillance at issue in Chatrie was far less extensive and revealing than the long-term surveillance at issue in Carpenter. He advocated for the traditional third-party doctrine and argued that cellphone users should have no Fourth Amendment rights in their Location History data because they voluntarily disclose it, in the sense that they can easily live without Location History. This granular approach to voluntariness (“can a user go without this particular app or service?”) is less realistic and appropriate than the majority’s holistic approach (“can a person realistically use their cellphone without using apps or disclosing data?”). In the digital world, making everything turn on voluntariness is a bad approach in any event. But Alito’s argument here is colorable.
Justice Alito’s discussion of whether the Court should have taken the case in the first place was, by contrast, a bit wild. He argued that the Court should not have granted cert on the Fourth Amendment search issue because the Fourth Circuit also resolved the case on good faith exception grounds, meaning that the police relied in good faith on a search warrant. Because Chatrie will inevitably lose on the same grounds on remand, Alito wrote, the Court’s opinion is “advisory,” albeit not in the jurisdictional sense because Alito concedes that it is a “case or controversy” that the Court can properly hear. It is difficult to make sense of Alito’s argument. As the majority noted, the seminal good faith exception case said that courts should feel free to resolve merits questions before good faith exception questions, in order to guide future action by police officers. Alito also seemed to argue that the Supreme Court should never review Fourth Amendment cases involving novel issues, i.e., cases where the good faith exception applies, and should permanently bar defendants from obtaining relief in such cases. He would not have granted this case because “it would be nearly impossible for Chatrie to prove that the police here ... acted in bad faith.” It’s impossible because “this Court has never provided guidance” on the relevant issues. But there’s a Catch-22 here. Alito’s argument is that the Court should acknowledge that defendants can never win on novel Fourth Amendment issues and that the Court should never grant cert to resolve novel Fourth Amendment issues. To adopt this approach would be to abdicate the Court’s responsibility to say what the law is.
In a complex and novel case involving digital technology, the majority of the Court got Chatrie right, finding that geofence surveillance is a Fourth Amendment search requiring a warrant and probable cause. Resolving such a case correctly is no mean feat. Perhaps the Justices are both tech-savvy and wise. Perhaps they just checked their phones and found they had Location History switched on, as the vast majority of Google Maps or Google Assistant users in the US likely do. In any event, they preserved meaningful Fourth Amendment rights in the digital age and charted the course of Fourth Amendment law for years or decades to come.
-- Matthew Tokson