Gorsuch signaled his views at the end of the first half of the argument in this exchange with Carpenter’s lawyer:
Gorsuch: Focusing on the property-based approach, putting aside reasonable expectation for just a moment, what do we know about what state law would say about this information?
So say—say a thief broke into T-Mobile, stole this information and sought to make economic value of it. Would you have a conversion—would your client have a conversion claim, for example, under state law? Have you explored that at all?
When Wessler responded that state courts hadn’t explore the possibility, Gorsuch returned to the theme at length in questioning the government’s lawyer, Michael Dreeben:
Gorsuch: Mr. Dreeben, I’d like to—I’d like to drill down on that and return to Justice Kagan’s question. You know, the facts here wind up looking a lot like Jones.
One thing Jones taught us is—and reminded us, really, is that the property-based approach to privacy also has to be considered, not just the reasonable expectation approach.
So, if we put aside the reasonable expectation approach for just a moment, Katz, Miller, Smith, and ask what is the property right here, let’s say there is a property right. Let’s say I have a property right in the conversion case I posited with your colleague. So that if someone were to steal my location information from T-Mobile, I’d have a conversion claim, for example, against them for the economic value that was stolen. Wouldn’t that, therefore, be a search of my paper or effect under the property-based approach approved and reminded us in Jones?
After Dreeben fought the hypothetical, Gorsuch suggested that federal law had already created a property right in the cellphone data by declaring, in section 222 of the Wireless Communication and Public Safety Act of 1999, that “every telecommunications carrier has a duty to protect the confidentiality of proprietary information of, and relating to … customers.” (For an elaboration of the argument that Gorsuch was invoking, read Richard Re and Will Baude’s posts on the Positive Law Model of the Fourth Amendment.) Gorsuch went on to suggest that the Fourth Amendment might prohibit Congress from violating the property right it had created by allowing the data to be seized without a warrant.
Gorsuch: So—so the government can acknowledge a property right but then strip it of any Fourth Amendment protection. Is that the government’s position?
Dreeben: No, no, but I think that the—
Gorsuch: And so—so could we also say maybe that they also get this property right subject to having a non-Article III judge decide the case, or quartering of troops in your home? Could we strip your property interests of all constitutional protection?
Dreeben: Well, those are pretty far afield. I—I think what’s going on here—
Gorsuch: But does Congress’s determination also yield in the face of the Fourth Amendment, Mr. Dreeben?
Dreeben: It does not.
Gorsuch: It does not. The Fourth Amendment is trumped by this statute?
Dreeben: But what interests the statute —
Gorsuch: In the government’s—in the government's view. Is that—is that right? The statute trumps the Fourth Amendment?
Dreeben: I think I said the opposite.
Gorsuch: Oh, good. All right. I hoped so.
At this point in the argument, Sotomayor enthusiastically endorsed Gorsuch’s argument that Congress couldn’t trump the Fourth Amendment:
Sotomayor: Isn’t what that Congress did?
Dreeben: No, because Congress provided that it shall be disclosed as required by law. And the same Congress has passed—
Sotomayor: Well, but then we—then you’re begging the question, which is Justice Gorsuch’s question, which is what’s the—what does the law, the Fourth Amendment, require in those circumstances?
Dreeben: So this Court has been …
Sotomayor: You’re saying Congress can set the level of what the Constitution requires, but I don't know that that’s true.
And then Gorsuch clinched the point by comparing the warrantless search of private information to the general warrants that sparked the American Revolution:
Gorsuch: Mr. Dreeben, it seems like your whole argument boils down to if we get it from a third party we’re okay, regardless of property interest, regardless of anything else. But how does that fit with the original understanding of the Constitution and writs of assistance?
You know, John Adams said one of the reasons for the war was the use by the government of third parties to obtain information forced them to help as their snitches and snoops. Why—why isn’t this argument exactly what the framers were concerned about?
Chief Justice Roberts invoked the same eloquent analogy in his unanimous opinion for the Court in Riley v. California in 2014, where he quoted John Adams and compared the warrantless search of a cellphone on arrest to the general warrants that sparked the American Revolution. “Modern cellphones are not just another technological convenience,” Roberts wrote. “With all they contain and all they may reveal, they hold for many Americans “the privacies of life. … The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought.” In the Carpenter argument, Roberts questioned the government’s argument that we voluntarily turn over private data to cellphone companies and therefore abandon expectations of privacy in the data. “That sounds inconsistent with our decision in Riley,” Roberts noted, “which emphasized that you really don’t have a choice these days if you want to have a cellphone.”