We filed an amicus brief in a federal appellate case called United States v. Ackerman Friday, arguing something most of us already thought was a given—that the Fourth Amendment protects the contents of your emails from warrantless government searches.

Email and other electronic communications can contain highly personal, intimate details of our lives. As one court noted, through emails, “[l]overs exchange sweet nothings, and businessmen swap ambitious plans, all with the click of a mouse button.” In an age where almost all of us now communicate via email, text, or some other messaging service, electronic communications are, in effect, no different from letters, which the Supreme Court held were protected by the Fourth Amendment way back in 1878.

Most of us thought this was pretty uncontroversial, especially since another federal appellate court held as much in a 2010 case called United States v. Warshak. However, in Ackerman, the district court added a new wrinkle. It held the Fourth Amendment no longer applies once an email user violates a provider’s terms of service and the provider shuts down the user’s account.

Background on the Case

It’s hard to conceive how an agreement with your email provider to deliver and store your emails could eviscerate your Fourth Amendment rights. But that’s what the district court decided in Ackerman. AOL shut down Ackerman’s email account after its automated anti-child pornography filters were triggered by an image attached to one of his emails. Following federal law, AOL sent the email and attachments to the National Center for Missing and Exploited Children (NCMEC), which searched them, leading to an indictment on child pornography charges. Ackerman pleaded guilty but reserved his right to argue that the evidence used against him shouldn’t have been allowed because it was obtained through searches of his email without a warrant.

The case, which is now on appeal to the 10th Circuit Court of Appeals, has already been up to this court once before. In 2016, the Tenth Circuit, in an opinion written by then-judge Neil Gorsuch, determined NCMEC acted as a government agent when it opened Ackerman’s email and its attachments. The appellate court also held that because NCMEC did so without a warrant, its actions might have violated the Fourth Amendment if Ackerman had a reasonable expectation of privacy in his email. The Tenth Circuit then sent the case back to the district court to address that question.

Back at the district court, the government argued, and the court held, that Ackerman did not have a reasonable expectation of privacy in the single email and attachments after Ackerman violated AOL’s TOS and AOL shut down his account. The court reasoned that because AOL’s TOS prohibited users from engaging in illegal activity and said the company could take legal action for violations, Ackerman was on notice that there would be no objective reason for him to expect privacy over his emails once his account was suspended.

The District Court’s Logic Doesn’t Make Sense

The district court’s reasoning is simply wrong. Under the court’s logic, your Fourth Amendment rights rise or fall based on unilateral contracts with your service providers—contracts that almost none of us even read. As we argued in our brief, a company’s TOS should not dictate your constitutional rights. Companies draft terms of service to govern how their platforms may be used; these are rules about the relationship between you and your email provider, not you and the government.

Internet companies’ TOS—those lengthy, annoying, legalese missives that users must agree to—control what kind of content you can post, how you can use the platform, and how platforms can protect themselves against fraud. The terms of these contracts are extremely broad. Actions that could cause a provider to terminate your account for TOS violations include not just criminal activity such as distributing child pornography but also—as defined solely by the provider—things like sending an email containing a racial epithet, sharing a news article with your team at work without permission from the copyright holder, or marketing your small business to all of your friends without their advance consent. While some might find activities such as these objectionable or annoying, they shouldn’t result in losing your Fourth Amendment right to privacy over your emails.

Given the vast amount of storage many email providers offer, most of us now hold onto email for years. Accounts can hold tens of thousands of private, personal messages, photos, and videos, revealing intimate details about our private and professional lives. In 2010 the U.S. Circuit Court of Appeals for the Sixth Circuit recognized the important privacy interests we have in our email, and ruled in Warshak that email users have a Fourth Amendment-protected expectation of privacy in the communications they store with their email providers. This ruling has been adopted by every court that has dealt directly with the question of Fourth Amendment rights and email content. It is recognized by all the major communications service providers, who require a warrant before turning over contents of user communications to the government. And it’s followed by the government, which regularly seeks warrants to access user communications.

The trial court’s ruling in Ackerman allows private agreements like TOS to trump bedrock Fourth Amendment protections for private communications. The ruling doesn’t just affect child pornography cases—anyone whose account was shut down for any violation of TOS could lose Fourth Amendment protections over all the emails in their account. The Tenth Circuit should not allow such a sweeping invalidation of constitutional rights to stand.