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The Supreme Court struck a on Monday in favor of privacy in the digital age. When the police want private information from your smartphone, we now know that’s a search within the meaning of the Fourth Amendment. And, to conduct that search, the police are going to need to prove probable cause that a crime occurred and that you were involved in it. And, they’re going to need a reasonably specific warrant describing what’s going to be searched. And, a judge is going to have to approve every step in that search process.
You may think that all seems straightforward and reasonable enough. You may even be surprised that the law didn’t already give you those protections. But the case was a close one with only five justices full-throatedly vindicating the Fourth Amendment’s privacy protection goals.
The case came to the Supreme Court from a bank robbery that happened in Richmond, Virginia, in 2019. Police didn’t know who did it so they got what’s become known as a geofence warrant. The short version of what that means is that they got a warrant to force Google to tell the police, using Google’s Location History technology, who was in the vicinity of the bank when it got robbed. Google complied, and police used that information to identify a man named Okello Chatrie as a suspect in the case.
But this isn’t a case about cops and robbers. It’s a case about how cops use peoples’ private digital data to catch robbers. More than that, it’s a case about how private the data on your phone really is and when that privacy interest has to give way to the government’s law enforcement efforts.
I covered the Chatrie case for Slate back in 2022 when it was first ruled on by the federal district court in Richmond. There’s more detailed information there about how Google’s Location History services used to work back in 2019. While the tech has changed since then, the principles the court trumpeted today are evergreen.
Many of us have gotten used to the U.S. Supreme Court’s explanation of constitutional rights getting bogged down in dim history from the 18th century. These originalist arguments suggest that if Thomas Jefferson or James Madison didn’t have it in mind, then the Constitution doesn’t care much about it. Well, in happy news, the court said in Chatrie, implicitly, we don’t much care what James Madison thought about smartphone data privacy. Madison never heard of smartphones, and he sure didn’t write them in or out of the Constitution.
What the court said, instead, is that more than 90 percent of Americans today own a smartphone. And that means “they are likely addicted to apps and other services” and, because of that, the phones collect detailed information about “all aspects of a person’s life,” including where the phone is located at any given time.
And whoever has access to that information has the extraordinary ability to pry into a person’s private life. Justice Elena Kagan, writing the majority opinion, made clear just what “indisputably private” interests are implicated by our phones’ location tracking technology: trips, for example, 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.” It shouldn’t come as a surprise that you can be law-abiding and still have an expectation of privacy, but the court took the extra step of explaining that privacy isn’t just about keeping police out of your home or keeping your 401(k) balance a secret. All the little nooks and crannies of our lives enjoy Fourth Amendment protections.
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Most importantly, the court said that we don’t lose Fourth Amendment privacy protections in our smartphone data just because we share that data with Google or Apple or Facebook or any of the other proliferating apps that access it. When we carry our phones around with all that data, the court said, we still have a “reasonable expectation” of privacy. And just because we clicked “yes” on a terms and conditions page doesn’t mean that we have surrendered voluntarily our expectation that this information won’t be given away to the government just because they ask.
This idea, that we get to have privacy expectations even in information we’ve shared with faceless corporations, is the biggest idea in Chatrie. There are plenty of cases that say that once you give third parties (strangers and others) access to your private information, it’s not really reasonable to expect that information to stay private. But, building on and reinforcing the lessons of , a 2018 case involving cellphone tower locating data, Chatrie made clear that the third-party doctrine just doesn’t make sense when it comes to smartphone data privacy.
And it doesn’t.
Our lives are inextricably bound up in giant networks of data that begin, end, and intersect with 6-inch screens we carry around in our pockets. Just because we’re plugged into those networks doesn’t mean we don’t care about privacy anymore. If anything, we care about it more because we’re aware that our personal information is so much easier to exploit today than it was even a decade ago. As Kagan wrote, we should not “imagine that all of us are living in dumb flip-phone days. The point of carrying smartphones is to use what is on them—as Carpenter said, to use the apps and ‘services they provide. …. That is what has become a ‘pervasive and insistent’—even ‘indispensable’—’part of daily life.’ ”
The court rejected in Chatrie a number of unwelcome ideas if privacy protection is what you think of when you think of the Fourth Amendment.
First, the Fourth Amendment is rooted in privacy protection not property protection. Justice Neil Gorsuch, in his concurrence, explained he would have overturned important precedent to hold that Chatrie’s Fourth Amendment rights are limited to his property interest in his data, not his privacy interest in what the data means. The slender five justice majority said no thank you to that crabbed reading that leaves so much unprotected.
Second, the court did not shrink from this debate just because it may be that later courts will find that the warrant for Chatrie’s data was, in the end, legal. The court recognized that data privacy has never been more important. Leaving it to another day to lay out guideposts for data-related warrants risked leaving Americans’ privacy to the tender mercies of zealous law enforcement and profit-minded corporations. The court didn’t say it, but it could not have been far from the justices’ thinking that they were laying down privacy markers at the precise moment that A.I. innovations make data technology more powerful than ever.
Third, arguments that Chatrie and Carpenter lacked “support in 19th– or 20th-century understandings of the Fourth Amendment” only garnered a minority of justices’ votes. Depending on how you count, two votes, and likely as many as four, but in any event, not a majority of five. That’s a huge win for a practical-minded, t model of constitutional interpretation. And it’s a loss for a vision of the Constitution understood through the narrow prism of .
Big, serious-minded, aggressive stands for robust constitutional protection of individual rights, even the individual rights of accused criminals, are rare commodities. But they’re how you can tell we’re sticking up for the rule of law.
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By any measure, that’s a good day.