People have a reasonable expectation of privacy in their private digital communications such as email, and therefore the Fourth Amendment protects those communications. It's a simple extension of the Supreme Court’s seminal 1967 ruling in Katz v. United States that the Fourth Amendment protected a telephone conversation held in a closed phone booth. But in a brief recently filed in a criminal terrorism case arising from surveillance of a United States citizen, the government needs only a few sentences to argue this basic protection doesn’t apply, with potentially dramatic consequences for the rest of us.

United States v. Mohamud

Mohamed Mohamud is a Somalia-born naturalized U.S. citizen who was convicted in 2012 of plotting to detonate a car bomb at a Christmas tree lighting ceremony in Oregon. Shortly after he was arrested, he was given notice by the government that it had used evidence obtained under the Foreign Intelligence Surveillance Act (FISA) against him.

But it wasn’t until after Mohamud was convicted and just a few weeks before he was to be sentenced that the government belatedly gave him notice for the first time that it had also used evidence derived under Section 702 of the FISA Amendments Act (FAA). The government continues to withhold the details of the FAA surveillance, forcing Mohamud (and other defendants receiving delayed FAA notice) to raise generalized challenges to the constitutionality of the FAA based only on what is publicly known about Section 702 surveillance. Mohamud did exactly that in April, raising several legal challenges to the FAA and arguing he should receive a new trial.

The Government’s “Talking to a Foreigner” Exception to the Fourth Amendment

While there’s a lot unknown about Section 702 surveillance, we do know it authorizes the targeting of foreigners even when this “targeting” results in the “incidental” collection of constitutionally protected Americans’ communications. As a result, the government can “acquire” the contents of Americans’ e-mails, VOIP calls, chat sessions, and more when they communicate with people outside the US.

In its recently filed response to Mohamud’s motion to suppress and for new trial, the government concedes for the sake of argument that an American whose communications are “incidentally” collected as part of Section 702 surveillance has “constitutional interests at stake.” So far so good; these constitutional interests are in fact at the core of what the Supreme Court describes as the Fourth Amendment’s protection of “the privacy and security of individuals against arbitrary invasions by governmental officials.” But then the government dismisses this fundamental protection with one staggeringly broad passage:

The Supreme Court has long held that when one person voluntarily discloses information to another, the first person loses any cognizable interest under the Fourth Amendment in what the second person does with the information. . . . For Fourth Amendment purposes, the same principle applies whether the recipient intentionally makes the information public or stores it in a place subject to a government search. Thus, once a non-U.S. person located outside the United States receives information, the sender loses any cognizable Fourth Amendment rights with respect to that information. That is true even if the sender is a U.S. person protected by the Fourth Amendment, because he assumes the risk that the foreign recipient will give the information to others, leave the information freely accessible to others, or that the U.S. government (or a foreign government) will obtain the information.

It is true that individuals “assume the risk” that the people they communicate with will turn over a recording to the government. So, for example, in the cases the government cites in the passage above, United States v. White and Hoffa v. United States, the Supreme Court found there is no Fourth Amendment violation if you have a private conversation with someone who happens to be a government informant and repeats what you said to the government or even surreptitiously records it. In those instances, individuals’ “misplaced confidence” that people they are communicating with won’t divulge their secrets is not enough to create a Fourth Amendment interest.

But the government stretches these cases far beyond their limits, arguing that its own incidental collection of an American’s communications while targeting a foreigner is the same as having that person repeat what the American said to the government directly, even though it is the government that is eavesdropping on the conversation. In essence, when you communicate with someone whose communications are being targeted under the FAA, you have no Fourth Amendment rights. Under this reasoning, any time you send an email to someone in another country, you “assume the risk” that your intended recipient may be a foreigner and that the government can obtain the contents of the email without a warrant.

While it’s true you run the risk that your communications could be intercepted by the government if they’re wiretapping the person you’re speaking with, the government can only do that aggressive type of surveillance with prior approval from a judge after satisfying a number of stringent constitutional and statutory requirements in order to listen in. But the FAA contains none of these privacy safeguards.

The Non-Existent Fourth Amendment

Remarkably, the government goes even further—and highlights the real problem—in a later footnote:

Moreover, any expectation of privacy of defendant in his electronic communications with a non-U.S. person overseas is also diminished by the prospect that his foreign correspondent could be a target for surveillance by foreign governments or private entities[.]

So not only do you have no privacy in a conversation because the US may be listening in under Section 702, you’re also on notice that since the foreigner you’re talking to may be under surveillance by some other country, your expectation of privacy in your conversation is further “diminished.”

The implication of the government’s argument is that you have no Fourth Amendment protection in anything that could potentially be overheard by someone—either as the target of the United States under the FAA, or some other foreign country—or in information stored “in a place subject to a government search.” Under this logic, the Fourth Amendment is quite simply meaningless.

That’s because nearly everything is subject to a government search: from your electronic communications to your home to your physical body. The issue is not whether the government can search these areas but how they are able to do so. Traditionally the Fourth Amendment demands the government obtain a search warrant, demonstrating to a neutral and detached magistrate that there is probable cause to do a narrow, particular search to find evidence of a crime or other contraband.

If Fourth Amendment protections are gone the minute something is placed in an area accessible to any government, then there will be no need to obtain warrants or wiretap orders or any other judicial permission. The fact that something could be searched somewhere at sometime for some reason means that it is always fair game for the government. That ignores not only the traditional limitations of the government’s authority to search—generally with a probable cause warrant with limited exceptions—but the increasingly digital world we live in where our personal documents and communications are stored online in servers owned by others.

The hearing on Mohamud’s motion is June 4 in Portland, Oregon. We hope the court recognizes the dangerous breadth of this line of argument and rejects it.