You probably know the feeling: you reach for your phone only to realize it’s not where you thought it was. Total panic quickly sets in. If you’re like me (us), you don’t stop in the moment to think about why losing a phone is so scary. But the answer is clear: In addition to being an expensive gadget, all your private stuff is on there.

Now imagine that the police find your phone. Should they be able to look through all that private stuff without a warrant? What if they believe you intentionally “abandoned” it? Last week, EFF filed an amicus brief in Small v. United States asking the Supreme Court to take on these questions.

In Small, police pursued a robbery suspect in a high-speed car chase near Baltimore, ending with a dramatic crash through the gates of the NSA’s campus in Fort Meade, Maryland. The suspect left his car, and officers searched the area. They quickly found some apparently discarded clothing, but many hours later they also find a cell phone on the ground, over a hundred feet from the clothing and the car. Despite the intervening time and the distance from the other items, the police believed that the phone also belonged to their suspect. So they looked through it and called one of the stored contacts, who eventually led them to the defendant, Mr. Small.

The Fourth Circuit Court of Appeals upheld this warrantless search of Small’s phone under the Fourth Amendment’s “abandonment doctrine.” This rule says that police don’t need a warrant to search and seize property that is abandoned, as determined by an objective assessment of facts known to the police at the time. Mr. Small filed a petition for certiorari, asking the Supreme Court to review the Fourth Circuit’s decision.

EFF’s brief in support of Small’s petition argues police shouldn’t be able to search a phone they find separated from its owner without a warrant. That’s because phones have an immense storage capacity, allowing people to carry around a comprehensive record of their lives stored on their phones. And if you’ve ever experienced that panicky feeling when you can’t find your phone, you know that, despite their intimate contents, phones are all too easy to lose. Even where someone truly chooses to abandon a phone, such as when they turn in an old phone to upgrade to a new one, they probably don’t intend to abandon any and all data that phone can store or access from the Internet—think of cloud storage, social media accounts, and the many other files accessible from your phone, but not actually located there. As a result, we argue phones are unlike any other object that individuals might carry with them and subsequently lose or even voluntarily abandon. Even when it’s arguable that the owner “abandoned” their cell phone, rather than simply misplacing it, police should be required to get a warrant to search it.

If this reasoning all sounds familiar, it’s because the Supreme Court relied on it in a landmark case involving the warrantless search of phones all the way back in 2014, in Riley v. California. Riley involved the warrantless searches of phones found on suspects during lawful arrests. Even though police can search items in a suspect’s pockets during an arrest to avoid destruction of evidence and identify any danger to the officers, the Court recognized in its opinion that phones are different: “Modern cell phones are not just another technological convenience. With all they contain and all they may reveal, they hold for many Americans ‘the privacies of life.’” In a unanimous decision by Chief Justice Roberts, the Court wrote, “Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple — get a warrant.”

Even though the warrant rule in Riley seemed clear and broadly applicable, the lower court in Small ruled it was limited to searches of phones found on suspects during an arrest. That’s not only a misreading of everything the Supreme Court said in Riley about why phones are different than other personal property, it’s also a bad rule that creates terrible incentives for law enforcement. It encourages warrantless searches of unattended phones, which are especially likely to lead to trawling through irrelevant and sensitive personal information.

Losing a phone is scary enough; we shouldn’t have to worry that it also means the government has free rein to look through it. We hope the Supreme Court agrees, and grants review in Small. A decision on the petition is expected by June.