As Damon Root noted earlier today, Justice Neil Gorsuch's dissent from Carpenter v. United States reads more like a concurrence, agreeing with the majority's conclusion that police generally need a warrant to obtain cellphone location data but disagreeing with its reasoning. In fact, Gorsuch is bolder than the majority, recommending a broader reconsideration of the doctrine that says the Fourth Amendment imposes no limits on the government's access to information that people entrust to third parties. At the same time, Gorsuch agrees with Clarence Thomas, who also filed a dissent in Carpenter, that it makes little sense to draw the boundaries of Fourth Amendment rights based on expectations of privacy that judges deem reasonable.
The Supreme Court developed the third-party doctrine in United States v. Miller, a 1976 case dealing with bank records, and Smith v. Maryland, a 1979 case involving "pen registers" that record the phone numbers called from a particular location. As the Court explained the principle in Miller, "the Fourth Amendment does not prohibit the obtaining of information revealed to a third party and conveyed by him to Government authorities, even if the information is revealed on the assumption that it will be used only for a limited purpose and the confidence placed in the third party will not be betrayed." Gorsuch recognizes the sweeping implications of that principle in an age when sensitive information is routinely stored on remote servers:
What's left of the Fourth Amendment? Today we use the Internet to do most everything. Smartphones make it easy to keep a calendar, correspond with friends, make calls, conduct banking, and even watch the game. Countless Internet companies maintain records about us and, increasingly, for us. Even our most private documents—those that, in other eras, we would have locked safely in a desk drawer or destroyed—now reside on third party servers. Smith and Miller teach that the police can review all of this material, on the theory that no one reasonably expects any of it will be kept private. But no one believes that, if they ever did….
Can the government demand a copy of all your e-mails from Google or Microsoft without implicating your Fourth Amendment rights? Can it secure your DNA from 23andMe without a warrant or probable cause? Smith and Miller say yes it can…But that result strikes most lawyers and judges today—me included—as pretty unlikely.
Sonia Sotomayor, who joined the majority opinion in Carpenter, expressed similar concerns in United States v. Jones, the 2012 decision that said monitoring a suspect's movements by attaching a GPS tracker to his car counts as a "search" under the Fourth Amendment. In that case, Sotomayor observed that the third-party doctrine is "ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks."
Gorsuch notes that "the Court has never offered a persuasive justification" for the third-party doctrine. A person's willingness to share information with someone else for a particular purpose does not imply that he is willing to share it with the world, and his awareness of the risk that it will nevertheless be divulged to others does not give those people permission to peruse it. Gorsuch draws an analogy to paper mail, which the Supreme Court since the 19th century has recognized as protected by the Fourth Amendment because the sender entrusts it to the postal service for delivery. The content of letters is protected even though people surrender possession of them and understand that they may be vulnerable to snooping.
Gorsuch is equally leery of linking Fourth Amendment rights to a "reasonable expectation of privacy," as the majority does in Carpenter. That standard, which was invented in the 1967 eavesdropping case Katz v. United States, is hard to apply in a principled way, since everything depends on which expectations count as reasonable, a question judges may not answer the same way most people would. "Katz has yielded an often unpredictable—and sometimes unbelievable—jurisprudence," Gorsuch writes, citing a couple of examples (citations omitted):
Take Florida v. Riley, which says that a police helicopter hovering 400 feet above a person's property invades no reasonable expectation of privacy. Try that one out on your neighbors. Or California v. Greenwood, which holds that a person has no reasonable expectation of privacy in the garbage he puts out for collection. In that case, the Court said that the homeowners forfeited their privacy interests because "[i]t is common knowledge that plastic garbage bags left on or at the side of a public street are readily accessible to animals, children, scavengers, snoops, and other members of the public." But the habits of raccoons don't prove much about the habits of the country. I doubt, too, that most people spotting a neighbor rummaging through their garbage would think they lacked reasonable grounds to confront the rummager.
Gorsuch also notes that the Katz test has little to do with the text of the Fourth Amendment, which makes no mention of expectations or of privacy per se. Rather, the amendment protects "the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." That guarantee, as Thomas shows in his dissent, is intimately related to property rights. "This case should not turn on 'whether' a search occurred," he writes. "It should turn, instead, on whose property was searched."
For Thomas, the answer is clear: The property belonged not to Timothy Carpenter, whose location records were used to implicate him in a series of armed robberies, but to MetroPCS and Sprint, the companies that provided his cellphone service. Gorsuch, by contrast, thinks it's "entirely possible a person's cell-site data could qualify as his papers or effects under existing law." He notes that federal law treats those records as "customer proprietary network information," which people generally cannot obtain without the customer's permission.
Gorsuch sees advantages to "a Fourth Amendment model based on positive legal rights," as advocated by a brief the Institute for Justice filed in Carpenter, which draws on the work of law professors William Baude (University of Chicago) and James Stern (William & Mary). Under that model, the Fourth Amendment is implicated whenever the government seeks special access to information that ordinary people cannot legally see without the subject's consent. That approach offers a promising alternative to the infinitely malleable Katz test, which invites judges to constitutionalize their own privacy preferences, and a Fourth Amendment that covers your data only as long as you retain physical possession of it.