Judge Neil Gorsuch is one of my favorite judges, and I don’t lightly or often take issue with his opinions. But on Friday, Gorsuch handed down an important Fourth Amendment case that has a somewhat puzzling section with far-reaching implications. The case, United States v. Ackerman, considers how the Fourth Amendment applies to a child pornography detection system set up by Internet service providers and the National Center for Missing and Exploited Children (NCMEC). The opinion holds that NCMEC is governed by the Fourth Amendment and that it cannot open emails that providers did not themselves open without triggering the Fourth Amendment.

I don’t have a difficulty with that conclusion. On the other hand, I was puzzled by the panel’s alternative holding that reached the latter result a second time under the United States v. Jones trespass test. That alternative holding isn’t necessarily wrong, but it takes a lot of non-obvious steps without much explanation. With my apologies for writing a post that may be of interest only to the serious Fourth Amendment nerds among the readership, I thought I would say more about why that second holding matters and why I’m puzzled by it.

First, the facts: America Online (AOL) voluntarily scans outgoing emails for known images of child pornography. When it gets a positive hit, as it did with an email from the defendant, it sends the email and its attachments to NCMEC. NCMEC then opens the email and all of its attachments, and if it finds evidence of child pornography, it refers the case to criminal investigators. In this case, NCMEC had a positive hit on a picture file that was one of four attachments to an email sent by the defendant. AOL’s software forwarded the email with its four attachments to NCMEC. NCMEC opened the email and all four attachments and then referred the case to the authorities. No warrant was obtained.

The legal question is, how does the Fourth Amendment apply? AOL was assumed to be a private actor not regulated by the Fourth Amendment. But what about NCMEC? The district court held that NCMEC is a private actor for Fourth Amendment purposes and that even if NCMEC is a state actor, it did not expand on AOL’s private search under the private-search reconstruction doctrine.

The Tenth Circuit disagreed on both counts. The first part of the opinion concludes that NCMEC is the government for Fourth Amendment purposes, and that even if it isn’t, it acted as an agent of the government here. The second part of the opinion concludes that the court won’t reach the broad issue of whether the emails are protected under the Fourth Amendment, but that to the extent e-mails are protected, the government can’t rely on the Internet provider’s private search under the private-search reconstruction doctrine. AOL only scanned the email and images, found a positive hit on an attachment, and then forwarded the email and attachments to NCMEC. NCMEC did more, as it opened the message sent to it by AOL and thus saw the email and all of the attachments.

This strikes me as essentially endorsing the file-by-file approach to the private-search reconstruction doctrine that is currently the subject of an ever-deepening circuit split. Granted, it’s somewhat skipping over what may be the most important implication of its analysis, that AOL’s copying the files and sending them in a separate message to NCMEC were not acts that (if undertaken by the government) would be an additional search. But I think that implication would be correct, at least if I understand the technology correctly.

So far, so good. And as the court recognizes, the government can always just get a warrant after the positive hit anyway.

The next part of the opinion takes an unexpected turn. Gorsuch (joined here only by Judge Phillips) concludes that NCMEC’s opening the electronic message from AOL was also a physical intrusion or trespass into the defendant’s “effects” and therefore was a search under United States v. Jones. Here’s the key passage, which appears after a discussion of United States v. Jacobsen (more on that later):

Given the uncertain status of Jacobsen after Jones, we cannot see how we might ignore Jones’s potential impact on our case. And its impact here seems even clearer than in Jacobsen. After all, we are not dealing with a governmental drug test that destroyed but a trace amount of potential contraband. We are dealing instead with the warrantless opening and examination of (presumptively) private correspondence that could have contained much besides potential contraband for all anyone knew. And that seems pretty clearly to qualify as exactly the type of trespass to chattels that the framers sought to prevent when they adopted the Fourth Amendment. See, e.g., 1 Thomas M. Cooley, The General Principles of Constitutional Law in the United States of America 212 & n.2 (1880); Thomas M. Cooley, A Treatise on the Constitutional Limitations Which Rest upon the Legislative Power of the States of the American Union 306 n.2 (1868); Ex parte Jackson, 96 U.S. at 733. Of course, the framers were concerned with the protection of physical rather than virtual correspondence. But a more obvious analogy from principle to new technology is hard to imagine and, indeed, many courts have already applied the common law’s ancient trespass to chattels doctrine to electronic, not just written, communications. See, e.g., eBay, Inc. v. Bidder’s Edge, Inc., 100 F. Supp. 2d 1058, 1063, 1069-70 (N.D. Cal. 2000); CompuServe Inc. v. Cyber Promotions, Inc., 962 F. Supp. 1015, 1019,1027 (S.D. Ohio 1997); Thrifty-Tel, Inc. v. Bezenek, 46 Cal. App. 4th 1559, 1565-67 (1996). So it seems that, whether we analyze the “search” question through the lens of the government’s preferred authority — Jacobsen and Katz — or through the lens of the traditional trespass test suggested by Jones, they yield the same (and pretty intuitive) result: NCMEC conducted a “search” when it opened and examined Mr. Ackerman’s email.

A few thoughts:

1) I think, although I’m not entirely sure, that this discussion counts as an alternative holding rather than as just dicta. See, e.g., Surefoot LC v. Sure Foot Corp., 531 F.3d 1236, 1243 (10th Cir. 2008) (“Alternative rationales such as this, providing as they do further grounds for the Court’s disposition, ordinarily cannot be written off as dicta.”). If that’s right, it amounts to a binding interpretation of the Tenth Circuit on the meaning of the Jones trespass test.

2) As I detailed in “The Curious History of Fourth Amendment Searches,” there is considerable uncertainty about what kind of test Jones creates. There was no pre-Jones trespass test, so it’s now up to courts to identify what kind of trespass test Jones requires. I had thought, after Florida v. Jardines, that the test was probably just physical intrusion into a suspect’s property. The Seventh Circuit has suggested a similarly physical approach in United States v. Sweeney. Under Sweeney, establishing a Jones trespass requires first establishing “possession of the property in question” and, second, establishing “the ability to exclude others from entrance onto or interference with that property.”

Given that context, it’s notable that Gorsuch endorses a much less physically based approach to the test. The decision states that the legal standard is trespass to chattels, and specifically (he suggests in the Jacobsen discussion) the late 18th-century version of that tort. Justice Alito hinted at that standard in his Jones concurrence, although as I detail in my article, it’s hardly obvious that this is correct.

Gorsuch also cites Cooley’s writing and Ex Parte Jackson for support, but it’s not clear to me that they help. Jackson recognized that sealed postal letters are protected by the Fourth Amendment, but it didn’t say that the test is trespass or that the trespass test applies to virtual property. In a brief search, I only found later versions of Cooley’s work online. Perhaps a better discussion is in the earlier versions. But what I saw didn’t reach that issue, either. The later edition of Cooley’s 1880 treatise that I found does say that Fourth Amendment protection “extends to one’s person and papers, wherever they may be.” But that was written in the wake of Boyd v. United States (1886), which focused on privacy instead of property. Because the trespass test wasn’t adopted until the Jones case in 2012, it’s hard to know what Boyd-era privacy discussions show.

3) If the Fourth Amendment adopts the trespass-to-chattels tort, the next question is why the elements of the tort were satisfied on the facts here. Gorsuch doesn’t give us the details. Instead he draws an analogy between snail mail and email, apparently on the thinking that the analogy itself does the work: “a more obvious analogy from principle to new technology is hard to imagine.” I agree that the two are analogous. But why does that analogy matter? The idea behind the Katz reasonable-expectation-of-privacy test was that a trespass approach does not allow you to you draw analogies “from principle to new technology.” If the test is property, then you end up with different results in a world of physical stuff and non-physical stuff. The Katz court didn’t want to limit the Fourth Amendment in that way in a technological age, so it rejected property as the guide (or at least as the only guide).

Put another way, much of the point of Katz was to allow us to draw the technological analogies that preserve the role of the Fourth Amendment over time. Given that, I was surprised that the opinion draws analogies from physical property to their virtual analogies under the trespass approach that Katz purported to refute. If you can adopt that reasoning under trespass, it’s not clear why you need Katz. I have wondered before if Justice Scalia ultimately would have wanted a broad view of trespass to be able to bring in enough of Katz that he could persuade others on the Court to drop Katz entirely. But that’s just speculation.

4) I was also not sure of by how trespass to chattels applied here. If I’m understanding the technology correctly, NCMEC’s action consisted of opening a file on its own server. I take the court to be saying that NCMEC’s opening the file on its own server was a trespass into the defendant’s property. This would mean that the defendant had a separate property right in his data that was distinct from NCMEC’s merely physical property right in the server. If I’m right about that, it raises a lot of questions. What exactly is the chattel, what counts as infringement of it, and who is liable under what circumstances for the infringement?

These questions seem notably different from those addressed in the (controversial) 15-to-20-year-old civil trespass cases the opinion cites. As best I recall those cases, the property that was being trespassed was still ultimately physical. The claim was that communicating to and through the party’s network in unwanted ways was a trespass into the physical server by the electronic signals. The trespass-to-chattels argument in this case seems different. Instead of trespass to chattels potentially recognizing a right of network owners to keep people out of their networks, the concept is being applied to say that network owners cannot access files sent to them and residing on their own server because they are the property of someone else.

5) It’s worth wondering whether any of this discussion was necessary. It’s at most an alternative holding for a conclusion already reached under the Katz test. And as far as I can tell, it wasn’t an issue the parties raised. I skimmed over the parties’ briefs, and Jones was only cited once, in a footnote, and only in a string cite for the view that the Katz expectation-of-privacy test is still part of the Fourth Amendment. (There might be more in an amicus brief, as several were filed; I didn’t check them all.) Maybe this was the first round in a broader rethinking of the trespass test, but I think its brief presentation leaves a lot of big questions unanswered.

Finally, I mentioned that the opinion also sheds doubts on the continuing viability of United States v. Jacobsen. That discussion is pretty interesting, too, so I thought I would discuss it for the seven readers still with me this far down.

Jacobsen ruled (among other things) that field-testing narcotics is not a “search” because it doesn’t reveal significant information under the Katz test. Gorsuch speculates that testing drugs may be now a search because it is a trespass into the person’s property under Jones:

Reexamining the facts of Jacobsen in light of Jones, it seems at least possible the Court today would find that a “search” did take place there. After all, the DEA agent who performed the drug test in Jacobsen took and destroyed a “trace amount” of private property, 466 U.S. at 125, a seeming trespass to chattels. Neither is there any question that the purpose and effect of the agent’s action was to obtain information. See id. at 122-23. And while the destruction of only a “trace amount” of private property might not amount to a trespass under modern tort law, even less was required to establish a claim of trespass to chattels at the time of the founding — and we know the Fourth Amendment is no less protective of persons and property against governmental invasions than the common law was at the time of the founding. Jones, 132 S. Ct. at 950, 953; id. at 957 n.2 (Alito, J., concurring in the judgment) (“At common law, a suit for trespass to chattels could be maintained if there was a violation of ‘the dignitary interest in the inviolability of chattels,’ but today there must be ‘some actual damage to the chattel before the action can be maintained.’” (quoting W. Keeton et al., Prosser & Keeton on Law of Torts § 14, at 87 (5th ed. 1984))).

This is an interesting possibility. On one hand, I do think there’s a good claim that Jones makes some kinds of chemical testing a search that might not be a search under Katz. (As regular readers may recall, I argued in a later-denied cert petition that DNA-testing blood found on a suspect’s shirt is a Fourth Amendment search under Jones.) On the other hand, I’m not sure how this applies to destroying part of a substance in an effort to answer whether it is contraband. If the Jones trespass test is based on property law, then what do you do with the fact that by definition you can’t have a property right in contraband? How can you have a property-based Fourth Amendment right in an item that cannot be your property? I’ve sometimes thought this was the problem that led the Court in Jacobsen to focus on the information revealed instead. Otherwise you end up with the somewhat odd answer that whether field testing is a search depends on whether the government’s hunch that the substance was contraband was later shown to be correct. All of this amounts to an interesting line of thinking that creative defense counsel might push, although it’s not clear to me where it leads.