The tech world is abuzz because Apple has announced it will fight a court order requiring it to develop a custom version of its iOS operating system so the FBI can hack into an iPhone that belonged to one of the San Bernardino terrorists. We don’t know exactly what legal claims Apple will raise—it will probably argue that the order exceeds the court’s statutory authority, and there may be some dispute about the strength of the government’s law enforcement and national security needs in this particular matter. But some speculate that Apple may go further and argue that the order actually violates the Constitution. That’s where things get interesting.

Apple Inc. is a corporation—an artificial legal entity that exists because of a charter granted under the laws of California. Corporations are not people, and they shouldn’t be treated as if they have constitutional rights like living, breathing people.

But that doesn’t mean Apple doesn’t have a case. It just needs to rely on an old legal doctrine with a Latin name, and forty-year-old precedent involving beer sales in Oklahoma.

According to pundits, Apple is expected to argue that the court order violates the Fourth Amendment. The question is whose Fourth Amendment rights are at stake. Apple’s claim as a corporation is weak. As the Supreme Court has recognized, “corporations can claim no equality with individuals in the enjoyment of a right to privacy. They are endowed with public attributes. They have a collective impact upon society, from which they derive the privilege of acting as artificial entities.”

But there’s someone who does have a right to privacy at issue here: Apple’s customers! Giving in to the government’s demand here could both create a broader vulnerability in iOS, and set a precedent for allowing the government to require backdoors in general. Unfortunately, customers whose privacy might be at stake in future cases can’t easily come into court to challenge the order.

That’s where the ancient legal doctrine known as jus tertii (in English, third-party standing) comes in. Usually, when you go to court, you have to argue your own rights, not someone else’s, were violated. But under jus tertii, sometimes X can go into court and argue that Y’s rights are at stake. Courts don’t always allow these claims—there’s a four-part test—but there are legitimate circumstances, and this might be one.

The classic jus tertii case involved an Oklahoma law that set different drinking ages for males (21) and females (18). The question was whether the law unconstitutionally discriminated against young men on the basis of sex. But the plaintiff in the Supreme Court wasn’t a 19 or 20-year-old man. Rather, the Court allowed the case to be argued by a (female) beer vendor. The beer vendor hadn’t been discriminated against at all, but her male customers had, and she came into court and argued a sex-discrimination claim on their behalf. And she won!

That’s the model that makes sense here.  As a corporation, Apple doesn’t have constitutional “privacy” rights of its own. But its customers do. This isn’t one of the all-too-common scenarios where corporations make constitutional arguments that have no connection to the constitutional rights of any living, breathing people. Here, where the court order threatens to compromise the privacy of people who aren’t even involved in the court case, Apple might well be the best, or only, party to raise claims based on iPhone customers’ privacy rights. And letting Apple make legal arguments based on its customers’ rights is far sounder than indulging the fiction that a multinational corporation is a “person” with inalienable rights under our Constitution.