As Justice Samuel Alito has lamented, “today, some of the greatest threats to individual privacy may come from powerful private companies that collect and sometimes misuse vast quantities of data about the lives of ordinary Americans,” but the Fourth Amendment offers no protection whatsoever because “it restricts the conduct of the Federal Government and the States, [but] does not apply to private actors.” He is not alone in his frustration. Professor Shoshana Zuboff points out that we live in an age of “surveillance capitalism” where technology companies gather, aggregate, store, and analyze vast amounts of information, providing them with intimate pictures of our lives and the opportunity to manipulate our thoughts and actions, often to the detriment of our individual lives and democratic society. This all seems, well, “unreasonable.” Yet, by virtue of the state agency requirement, the Fourth Amendment seems to be stuck on the sidelines. Or is it?

This Article challenges the unstated premise in Justice Alito’s syllogistic dirge: that powerful technology companies who threaten “the right of the people to be secure . . . against unreasonable searches” are not state agents for purposes of the Fourth Amendment. As we shall see, many of these “private” companies are state agents under well-established Fourth Amendment doctrine. They routinely share the fruits of their surveillance activities with the government, which has come to expect to benefit from “private” searches. Whether willing or unwilling they are, as privacy advocate Chris Hoofnagle has described them, “Big Brother’s little helpers.” Separately, many of these “private” surveillants have assumed roles in society once the sole province of governments. During oral argument in Moody v. NetChoice, Justice Ketanji Brown Jackson gave voice to rising sympathy for the view that, by virtue of the roles powerful social media companies play in contemporary society, they should not be insulated from First Amendment scrutiny based on the “public versus private distinction.” This Article argues that they likewise should not evade Fourth Amendment regulation.

Having argued that powerful “private” surveillants fall within the regulatory compass of the Fourth Amendment, the Article turns to practical consequences. In cases where the deployment and use of technology constitutes a search and there has not been user consent, the question is whether warrants are required. Because much of the surveillance conducted by powerful private companies is not for purposes of advancing normal criminal law enforcement goals, they are unlikely to be subjected to anything like a warrant requirement, at least in the first instance. Rather, what the Fourth Amendment demands are bespoke measures that strike a reasonable balance among legitimate corporate interests, the privacy interests of those surveilled, and public interests in safety and security. The Supreme Court provided one model in Carpenter v. United States, but there are others. Much depends on the nature of the technology at issue and the privacy, corporate, and government interests at stake.