The Supreme Court’s decision in Carpenter v. United States has lots of new directions in it. One direction that some commentators have focused on is its impact on the law of subpoenas. For example, Marty Lederman writes today that the subpoena analysis in Carpenter is “extraordinary” and “groundbreaking” and may trigger “a fundamental transformation of national subpoena practices.” In their dissents, Justice Alito and Justice Kennedy also suggest that the subpoena analysis in the case is a major break from the past.

I have a different view. There is a lot that is extraordinary and groundbreaking in Carpenter. But I think Carpenter makes only a small and likely necessary resolution of an unsettled question in the law of subpoenas. In this post, I will explain the problem and say why I think Carpenter doesn't have a major impact on subpoena law. I will also argue that if you think the majority is right on the law of searches, it is also likely right, at least as to the result, in its subpoena holding.

This is a really long post, so here’s a roadmap of where I’m going.

Part I introduces the two basic kinds of legal process in the law of criminal procedure: warrants and subpoenas. Part II explains how the dynamic of third-party storage alters the balance of criminal procedure law on which the two kinds of legal process are based. Part III shows that when a target has constitutional rights in remotely-stored information, there was a legal uncertainty before Carpenter on whether the subpoena rules continue to apply—but a good reason, rooted in a need to maintain the balance of the Fourth Amendment, to think they don’t.

Part IV turns to Carpenter and shows how the majority’s decision responds to the problems explained in Parts I-III. Finally, Part V argues that the majority’s approach to the law of subpoenas is only a small and likely necessary resolution of how the subpoena doctrine applies that should have relatively limited impact on the law of criminal procedure.

I. The Two Paths of Legal Process

Imagine the government believes that a person possesses evidence of crime in his home. Investigators want to get that evidence. But how? The law traditionally provides two forms of legal process to do it.

The first path, and the most familiar, is to get a warrant. A warrant authorizes the investigators to physically break into the place where the evidence is thought to be, rifle through the place, and take away the evidence they find.

A warrant is the best known form of government legal process in criminal investigations. But it’s not the only one. The government can also obtain evidence using a grand jury subpoena. A grand jury subpoena directs its recipient to bring the described evidence to the grand jury at some future place and time. Unlike a warrant, the police don’t barge in and take stuff. Rather, the subpoena recipient is tasked with gathering the evidence himself, from the stuff in his possession, and later bringing the evidence to the grand jury (or the police/prosecutors working with the grand jury).

Recognizing these two path matters because they are regulated by two very different legal regimes. When the government gets a search warrant, the Fourth Amendment is the big limit on the police. The police need to show probable cause to believe that the evidence will be located in the place to be searched. They need to specifically describe the place to be searched, and they need to describe specifically the evidence that they are seeking.

The law of grand jury subpoenas for evidence is very different. The Fourth Amendment applies, but its role is modest. No probable cause is required to issue a subpoena. The government can issue a subpoena—in the name of the grand jury, but really by the prosecutors who run the grand jury—just to see if a crime might have been committed. A recipient does have Fourth Amendment rights at stake, but he can challenge the subpoena only on the ground that it is overbroad or compliance is overly burdensome.

The flip side is that the recipient of a subpoena can challenge it under the Fifth Amendment right against self-incrimination. The recipient can claim that complying with the subpoena implies certain statements—that the records exist, that the recipient has them, and that the recipient thinks that they are authentic—and that he can’t be forced to testify against himself.

Note the key difference. When investigators want to break in and get the evidence themselves, they proceed by way of a warrant and the Fourth Amendment is the big legal barrier. When investigators want to have the evidence produced for them, they proceed by way of a subpoena and the Fifth Amendment is the big legal barrier. Two different paths with two different legal regimes limiting government access.

II. What Changes When A Target’s Evidence Is Stored With A Third Party?

Now let’s complicate matters. Let’s imagine that a target of an investigation has stored his evidence with someone else. Maybe Alice leaves a box of her personal files with Bob to store in Bob’s basement. Maybe Carl becomes a customer at a mailbox service that receives and stores his mail for him. Maybe David keeps his files stored in “the Cloud” with an online cloud service like Dropbox. In each of these cases, the person’s evidence is located far from them in the possession of another person or company.

Now imagine you’re the government, and you want to collect the suspect’s evidence. That evidence is now stored with a third party, whether it’s Bob, the mailbox service, or Dropbox. The question is, how does the fact of third-party possession change the legal framework? What law applies to collecting the evidence now?

The option to get a warrant and conduct the search directly remains. You could break in and take the evidence. That would be legal, but it’s probably a bit unseemly. For example, you probably don’t want local police breaking into Dropbox’s company headquarters and looking through its servers on their own to find a user’s files. And that wouldn’t be necessary, either, because the companies are just neutral parties. The police can work with them to retrieve the evidence. So even if a warrant is obtained, the police would want the third-party providers to gather the information. In effect, it would be a warrant that is executed like a subpoena.

But that brings us to the key question. Can the government still use a subpoena to get the information stored with third parties? Can they serve a subpoena on Bob for Alice’s box of files? Can they serve a subpoena on the mailbox service for Carl’s mail? Can they serve a subpoena on Dropbox for David’s files?

If you assume that none of the targets have Fourth Amendment rights in the records that they have stored with third parties, then the answer is easy. Not only can the government use a subpoena, but there is very little in the way of limits on that power. By hypothesis, the targets have no Fourth Amendment rights. And unlike with the subpoena stored by the target, there is no Fifth Amendment privilege to assert. This is a big difference. The Supreme Court held in Fisher v. United States that the recipients of a subpoena can’t assert the Fifth Amendment privilege of someone else. In addition, companies have no Fifth Amendment privilege to assert.

This means that if you assume no Fourth Amendment rights for the targets, the fact of third-party storage greatly shifts the legal terrain: It empowers the government by eliminating Fifth Amendment protection when the government wants to proceed by subpoena. The only constitutional limit now is that the possessors of the evidence can try to assert their modest Fourth Amendment objections based on the burdensomeness of complying with the subpoena. But in most cases that’s a very limited objection. And because the Internet and communications networks work using third parties, the shift to third-party storage is a really big deal.

Statutes can certainly come in and try to even the playing field. That’s exactly what the Stored Communications Act was designed to do. It imposes a court order requirement using the “reasonable suspicion” standard on access to unprotected records even though the Fourth Amendment doesn’t apply. But that’s a statute, not the Constitution.

III. The Puzzle of Fourth Amendment Rights in Records Stored With a Third Party

Now we get to the big question: How does the subpoena power apply if we assume that the target retains Fourth Amendment rights in the records stored with the third party? Imagine Alice has Fourth Amendment rights in the contents of the box she left with Bob. Imagine Carl has Fourth Amendment rights in the mail left with the mailbox service. And imagine David has Fourth Amendment rights in the files stored with Dropbox. Can the government subpoena those records from the possessor (Bob/mailbox/Dropbox) just like it could if the target had no Fourth Amendment protection in the records?

Appreciate the importance of the question. If the traditional subpoena rules continue to apply, then the fact of the target having Fourth Amendment rights in the information doesn’t matter all that much. The government can still just subpoena all the protected records, and they can do so without probable cause or even reasonable suspicion. The only apparent impact of finding the target has Fourth Amendment rights would be that the target has standing to challenge the subpoena. But because the only Fourth Amendment limit on the subpoena is the burdensomeness on the recipient of the subpoena, it’s not clear that this would matter.

If the traditional subpoena rules continue to apply, then, we end up with an equilibrium-adjustment problem: Applying the old law to the new facts of third-party storage may suddenly give the government a major power advantage by eliminating Fifth Amendment privilege from the subpoena equation. Technological change could put the government in a position where they could subpoena everything, with few limits, even if the target of the investigation has Fourth Amendment rights in the information.

Until Friday’s Carpenter decision, there was surprisingly little caselaw on what legal standard governed use of a subpoena on a third-party to collect information in which a target has Fourth Amendment rights. And believe me I have looked, as I’ve been interested in this issue for a long time. (I wrote an amicus brief partially on this question in 2002, and I had a section about it in the 2006 First Edition of my Computer Crime Law casebook.) The main reason for the absence of cases is the third-party doctrine. Under the third-party doctrine, targets usually don’t have any Fourth Amendment rights in the records the government might want to subpoena from the third party.

The sparse caselaw that does exist has tended to involve subpoenas to compel the possessor to hand over sealed documents when the government then obtained a warrant to open them. See, e.g., United States v. Barr, 605 F. Supp. 114, 119 (S.D.N.Y. 1985) (mail box service). But that doesn’t answer the question of whether a subpoena could be used to open the documents.

In other cases, courts simply said without any analysis that target Fourth Amendment rights meant that a warrant was required. See, e.g., United States v. Warshak, 631 F.3d 266, 288 (6th Cir. 2010) (holding that a user has Fourth Amendment rights in the contents of their remotely stored e-mail and therefore a warrant is required); United States v. Bach, 310 F.3d 1063, 1066 n.1 (8th Cir. 2002) (noting, in a case involving access to remotely stored e-mail, that the court “analyze[s] this case under the search warrant standard, not under the subpoena standard”)

Given all of this, the issue of whether a subpoena could be used to access target-protected data held by a third party was uncertain. For what it’s worth, my own view has been that if you recognize a target’s full Fourth Amendment rights in the records, then the subpoena standard is insufficient. As I wrote in a 2010 article (at page 1044), the reason is that a subpoena can compel a provider to hand over records but it can’t be used to open the constitutionally-protected set of records obtained. The government could in theory subpoena the records under my view, but it would still need a warrant to open them. A warrant is still required.

Until Carpenter, however, there was no Supreme Court discussion of the question

IV. The Subpoena Analysis in Carpenter

That brings us—finally!— to Carpenter. Up through page 18 of the Court’s opinion, the majority concludes that a cell phone user has Fourth Amendment rights in the cell phone provider’s cell site location records. The next question is what standard the government must satisfy to compel access to those records. The Chief Justice rather breezily concludes that a warrant is required, finding that the statutory Terry standard of the Stored Communications Act is insufficient.

The Chief Justice then turns to contrary arguments in Justice Alito’s dissent. In his dissent, Justice Alito notes that the traditional standard for compelling disclosure is the mere reasonableness subpoena standard. Because the statutory Terry standard is pretty much a subpoena with a required finding of reasonable suspicion, Justice Alito argues that the same constitutional analysis should apply to that court order as traditionally applies to subpoenas.

The Chief Justice disagrees with the following passage. This is the language that some think is a radical change, so it’s worth reprinting in full:

JUSTICE ALITO contends that the warrant requirement simply does not apply when the Government acquires records using compulsory process. Unlike an actual search, he says, subpoenas for documents do not involve the direct taking of evidence; they are at most a “constructive search” conducted by the target of the subpoena. Post, at 12. Given this lesser intrusion on personal privacy, JUSTICE ALITO argues that the compulsory production of records is not held to the same probable cause standard. In his view, this Court’s precedents set forth a categorical rule—separate and distinct from the third-party doctrine—subjecting subpoenas to lenient scrutiny without regard to the suspect’s expectation of privacy in the records. Post, at 8–19. But this Court has never held that the Government may subpoena third parties for records in which the suspect has a reasonable expectation of privacy. Almost all of the examples JUSTICE ALITO cites, see post, at 14–15, contemplated requests for evidence implicating diminished privacy interests or for a corporation’s own books. The lone exception, of course, is Miller, where the Court’s analysis of the third-party subpoena merged with the application of the third-party doctrine. 425 U. S., at 444 (concluding that Miller lacked the necessary privacy interest to contest the issuance of a subpoena to his bank). JUSTICE ALITO overlooks the critical issue. At some point, the dissent should recognize that CSLI is an entirely different species of business record—something that implicates basic Fourth Amendment concerns about arbitrary government power much more directly than corporate tax or payroll ledgers. When confronting new concerns wrought by digital technology, this Court has been careful not to uncritically extend existing precedents. See Riley, 573 U. S., at ___ (slip op., at 10) (“A search of the information on a cell phone bears little resemblance to the type of brief physical search considered [in prior precedents].”). If the choice to proceed by subpoena provided a categorical limitation on Fourth Amendment protection, no type of record would ever be protected by the warrant requirement. Under JUSTICE ALITO’s view, private letters, digital contents of a cell phone—any personal information reduced to document form, in fact—may be collected by subpoena for no reason other than “official curiosity.” United States v. Morton Salt Co., 338 U. S. 632, 652 (1950). JUSTICE KENNEDY declines to adopt the radical implications of this theory, leaving open the question whether the warrant requirement applies “when the Government obtains the modern-day equivalents of an individual’s own ‘papers’ or ‘effects,’ even when those papers or effects are held by a third party.” Post, at 13 (citing United States v. Warshak, 631 F. 3d 266, 283–288 (CA6 2010)). That would be a sensible exception, because it would prevent the subpoena doctrine from overcoming any reasonable expectation of privacy. If the third-party doctrine does not apply to the “modern-day equivalents of an individual’s own ‘papers’ or ‘effects,’” then the clear implication is that the documents should receive full Fourth Amendment protection. We simply think that such protection should extend as well to a detailed log of a person’s movements over several years. This is certainly not to say that all orders compelling the production of documents will require a showing of probable cause. The Government will be able to use subpoenas to acquire records in the overwhelming majority of investigations. We hold only that a warrant is required in the rare case where the suspect has a legitimate privacy interest in records held by a third party.

In his dissent, Justice Alito responds:

[The majority] decides that a “search” of Carpenter occurred within the meaning of the Fourth Amendment, but then it leaps straight to imposing requirements that—until this point— have governed only actual searches and seizures. See ante, at 18–19. Lost in its race to the finish is any real recognition of the century’s worth of precedent it jeopardizes. For the majority, this case is apparently no different from one in which Government agents raided Carpenter’s home and removed records associated with his cell phone. Against centuries of precedent and practice, all that the Court can muster is the observation that “this Court has never held that the Government may subpoena third parties for records in which the suspect has a reasonable expectation of privacy.” Ante, at 19. Frankly, I cannot imagine a concession more damning to the Court’s argument than that. As the Court well knows, the reason that we have never seen such a case is because—until today— defendants categorically had no “reasonable expectation of privacy” and no property interest in records belonging to third parties. See Part II, infra. By implying otherwise, the Court tries the nice trick of seeking shelter under the cover of precedents that it simultaneously perforates. Not only that, but even if the Fourth Amendment permitted someone to object to the subpoena of a third party’s records, the Court cannot explain why that individual should be entitled to greater Fourth Amendment protection than the party actually being subpoenaed. When parties are subpoenaed to turn over their records, after all, they will at most receive the protection afforded by [the subpoena cases] even though they will own and have a reasonable expectation of privacy in the records at issue. Under the Court’s decision, however, the Fourth Amendment will extend greater protections to someone else who is not being subpoenaed and does not own the records. That outcome makes no sense, and the Court does not even attempt to defend it.

V. What’s Happening Here, and a (Partial) Defense of the Majority’s Approach

What’s going on here? Although the majority could articulate the point a lot better than it did, I take it what the Court is doing is engaging in equilibrium-adjustment—one operating over the combination of the Fourth and Fifth Amendment together.

In a world of local storage, where suspects keep their evidence in their possession, the government has the two paths explained in Part I. They are limited by Fourth Amendment probable cause if they want to break in themselves, and they are limited by the Fifth Amendment right against self-incrimination if they want to compel records. But computers and the Internet are new worlds of remote storage. A typical Internet user has his protected records stored hundreds or thousands of miles away in the possession of big companies that have no Fifth Amendment rights and can’t assert them for their users. Applying the usual subpoena standard when the target has Fourth Amendment rights would result in a dramatic expansion of government power that would let the government get everything with few limits.

By insisting on a warrant requirement, the Court is restoring the prior equilibrium. Changing the legal rule when a third-party has Fourth Amendment rights in the information corrects for the otherwise distorting effect of third-party storage on the degree of legal protection. The same warrant rule applies that would apply if this were a traditional case of local storage. In effect, the Court’s approach collapses the two paths into one when there is third-party storage, which can account that the factual assumptions on which the legal framework for subpoenas has been generated– an environment in which targets are protected from subpoenas by the Fifth Amendment—no longer apply.

To be clear, I don’t think the Justices were thinking about the shift from the Fifth Amendment protection to the Fourth Amendment protection. I suspect they were just thinking about this as a Fourth Amendment. But the Chief Justice’s opinion recognizes that you need to have a full warrant protection for the third-party stored information or else the target’s newfound rights don’t mean much. As the Chief Justice states, “If the choice to proceed by subpoena provided a categorical limitation on Fourth Amendment protection, no type of record would ever be protected by the warrant requirement.”

All of this suggests that the operative legal rule here is that the existence of third-party rights triggers a higher protection for the third party to restore the equilibrium. As the Court holds, “a warrant is required in the rare case where the suspect has a legitimate privacy interest in records held by a third party.” If the government wants to get records that a suspect has stored, without the help of the suspect, the same warrant protection applies regardless of whether the suspect has stored the information at home or remotely.

This understanding illuminates important limits on the Court’s subpoena rule and shows why it will only apply “in the rare case.” For example, I gather that rule wouldn’t stop the government from issuing a subpoena to the target for the target’s records that he has stored in the Cloud, for example. The fact that the records are “held by a third party” doesn’t matter because the government isn’t getting the records from the third party but rather is going directly to the suspect. The Fifth Amendment issues would then control, leaving the two paths as they were without third-party storage.

Similarly, this approach shows why I disagree with this interpretation of Carpenter by Marty Lederman in his post today:

At a minimum, however, it is fair to assume that questions of the reasonable expectations of privacy of the "first party" subject of the records sought by production orders will now play a much larger role in subpoena litigation and other challenges to compulsory process.

I don’t think that’s right. Or at least I don’t think it shouldn’t be right. As I see it, the first party subject to the subpoena has all the protections it has always had: Mostly Fifth Amendment protections against complying with any subpoena under the act of production doctrine. That’s the traditional two paths described in part one, and I don’t think it changes in a case of local possession. Carpenter’s subpoena holding reflected a need for equilibrium-adjustment; it shouldn’t change anything in traditional cases where no equilibrium-adjustment is needed

To be sure, there are some difficult questions of application of the majority’s rule. I explored these issues a year ago in a long blog post, Third Party Rights and the Carpenter Cell-Site Case. For example, who gets notice of the government’s access? Who can object? As I wrote then:

Is the idea that a company served with a subpoena for business records has to figure out if the subpoena implicates only its own Fourth Amendment rights (in which case the subpoena complies with the Fourth Amendment so long as it is not overbroad) or if it also implicates a user’s Fourth Amendment rights (in which case the subpoena is insufficient and a warrant is required?). If the government issues a subpoena for business records and it turns out that a customer also had rights in the data, would we say that compelled compliance with the subpoena violated the rights of the user but not the company?

These are issues to work through, I recognize, but I gather they should apply only in “the rare case” when a third-party has stored records with a target’s protected information.

All of this is not to suggest that I think the majority’s subpoena holding has it quite right. I would have probably preferred the Court take the view I suggested in my 2010 article noted above, by which the government can still technically subpoena the records but can’t open the records without a warrant. This avoids the conceptual puzzles that Justice Alito notes by having the same rule apply in all situations: A subpoena can be used to compel records without probable cause, but the government needs a warrant to open Fourth Amendment protected records. That approach isn’t perfect, for reasons I explore in my article (see footnote 170). But I think it would be better.

Finally, I am certainly sympathetic with the concerns of Justice Alito and Justice Kennedy in their dissents. I think Carpenter’s search holding is wrong. In my view, users don’t have Fourth Amendment rights in their historical cell-site records. But if you accept that erroneous holding as correct, and you then need to figure out what the reasonableness standard is for compelling access, I think something like the majority’s rule, in which the target is still ultimately protected by the same protections that would apply if the information were locally stored, is probably right.

Carpenter creates a strange new world in a lot of ways. But I see its subpoena holding as more a necessary corollary to its search holding and not a groundbreaking departure in its own right.