Criminal Justice & the Rule of Law

Did the Ninth Circuit Create a New Fourth Amendment Notice Requirement for Surveillance Practices?

Orin Kerr
Wednesday, September 9, 2020, 7:01 AM

An overlooked part of United States v. Moalin could have a major impact on surveillance law.

A bird sits next to a surveillance camera. (Flickr/screenpunk,; CC BY-NC 2.0,

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This piece is cross-posted at the Volokh Conspiracy.

On Sept. 2, the U.S. Court of Appeals for the Ninth Circuit handed down a new decision, United States v. Moalin, on the telephony metadata program that Edward Snowden revealed in 2013. The opinion, by Judge Marsha Berzon, has drawn some attention for its rulings on the lawfulness of the now-expired program. But there’s a part of the opinion that has been mostly overlooked and which strikes me as much more important. Starting around page 36 of the opinion, the court appears to articulate a new Fourth Amendment notice requirement. It suggests that defendants charged with crimes must be notified about surveillance practices that led to evidence that may be used in their case.

This holding was easy to miss if you weren’t looking for it, in part because the court doesn’t even apply its own test. Because the defendants learned of the surveillance anyway, the court rules, there was no prejudice and the court doesn’t need to reach whether the notice requirement applied to the facts of Moalin. But although this passage ends up having no bearing on this one case, it strikes me as potentially a pretty big deal going forward for the field of surveillance law.

The Traditional Fourth Amendment Notice Requirement

Here’s the context. The Fourth Amendment traditionally has only one notice requirement. When the government executes a search warrant, the government has to give notice—even if delayed notice—that the warrant was executed. See, e.g., Dalia v. United States, 441 U.S. 238, 247-48 (1979). Normally the search itself will give notice, as it’s hard to miss when the police knock down your door and take away your stuff. But even if the search itself doesn’t provide notice, the government has to give post-search notice that the search occurred. See id.

In the past, at least, this notice requirement has been understood to be pretty modest. For example, say the government gets a warrant to seize all of your emails held by your email provider. The provider shares all of your emails, and the government looks through them. Do you get notice? No, the courts say. The Fourth Amendment notice requirement is satisfied by notice to the email provider rather than to you. The search occurred there, and what matters is that notice was provided where the search occurred. See, for example, United States v. Scully, 108 F. Supp.3d 59, 83-84 (E.D.N.Y. 2015).

The Ninth Circuit’s New Approach to Fourth Amendment Notice

Enter the new Ninth Circuit decision. As I read it, it has a very different concept of the Fourth Amendment’s notice requirement.

In Moalin, the question was whether defendants had to be notified about a warrantless national security program involving telephone metadata that had been collected about them as part of the investigation. I would have thought the answer is no. Most obviously, there was no search warrant about which to give notice. And beyond that, I would have thought the program under then-existing precedent not to be a search at all.

The Ninth Circuit imagines a different kind of notice requirement, though. Instead of a notice requirement that a warrant was executed, flowing from the warrant itself, this is a notice requirement that appears to be triggered only if and when criminal charges are filed providing notice that evidence about a person was collected using a surveillance practice that may or may not be a search. In effect, it’s a notice to criminal defendants to consider filing a motion to suppress to challenge the investigation and vindicate any Fourth Amendment rights that may or may not have been at stake.

Here’s the passage from the opinion reproduced in full:

The Fourth Amendment requires that a person subject to a government search receive notice of the search, absent “exigent circumstances.” Berger v. State of New York, 388 U.S. 41, 60 (1967); see United States v. Freitas, 800 F.2d 1451, 1456 (9th Cir. 1986). Courts have excused advance notice in the wiretapping context for a practical reason: if the subject of a wiretap were “told in advance that federal officers intended to record his conversations, the point of making such recordings would obviously [be] lost.” Katz, 389 U.S. at 355 n.16. In such circumstances, the government must provide a “constitutionally adequate substitute for advance notice.” Dalia v. United States, 441 U.S. 238, 248 (1979). Dalia explained that the Wiretap Act, which governs the use of electronic surveillance in criminal investigations, meets this requirement by instructing that “once the surveillance operation is completed the authorizing judge must cause notice to be served on those subjected to surveillance.” Id. (citing 18 U.S.C. § 2518(8)(d)); see United States v. Donovan, 429 U.S. 413, 429 n.19 (1977).

The government argues that Berger and Dalia are inapposite here because they dealt with ordinary criminal investigations, and the Fourth Amendment requirements are different in the foreign intelligence context. The government points to United States v. Cavanagh, which quoted United States v. United States District Court (Keith), 407 U.S. 297, 322–23 (1972), for the proposition that a different standard may be compatible with the Fourth Amendment in the intelligence-gathering context if it is “reasonable both in relation to the legitimate need of Government for intelligence information and the protected rights of our citizens.” 807 F.2d 787, 790 (9th Cir. 1987). Cavanagh held that “FISA satisfies the constraints the Fourth Amendment places on foreign intelligence surveillance conducted by the government.” Id.

For our purposes, the essential insight of Cavanagh is that even if the Fourth Amendment applies differently in the foreign intelligence context, it still applies, at least if U.S. persons are involved.

Cavanagh did not address the Fourth Amendment’s notice requirement, but the insight we glean from it bears on our analysis here: because the Fourth Amendment applies to foreign intelligence investigations, U.S. criminal defendants against whom the government uses evidence obtained or derived from foreign intelligence surveillance may have Fourth Amendment rights to protect. The principal remedy for a Fourth Amendment violation is the exclusionary rule: a criminal defendant may seek suppression of evidence obtained from an unlawful search or seizure, as well as of the “fruits” of that evidence—additional evidence to which it led. See Wong Sun, 371 U.S. at 488. But criminal defendants who have no knowledge that a potentially unconstitutional search has played a part in the government’s case against them have no opportunity to vindicate any Fourth Amendment-protected rights through suppression.

Notice is therefore a critical component of the Fourth Amendment in the context of a criminal prosecution. And although the Fourth Amendment may apply differently to foreign intelligence surveillance than to searches undertaken in ordinary criminal investigations, notice of a search plays the same role in the criminal proceeding: it allows the defendant to assess whether the surveillance complied with the Fourth Amendment’s requirements, whatever the parameters of those requirements are. Indeed, the Supreme Court has recognized that the notice provisions in FISA and the FAA serve precisely that function. See Amnesty Int’l USA, 568 U.S. at 421 & n.8.

At the same time, the need for secrecy inherent in foreign intelligence investigations justifies a more circumscribed notice requirement than in the ordinary criminal context. See Kris & Wilson, supra note 5, § 29:2 (discussing the need for secrecy). Whereas the Wiretap Act requires notice at the end of an investigation regardless of whether an indictment is filed, 18 U.S.C. § 2518(8)(d), the FISA and FAA notice provisions are more limited, requiring notice only when the “Government intends to enter into evidence or otherwise use or disclose in any trial ... or other proceeding in or before any court ... or other authority of the United States, against an aggrieved person, any information obtained or derived from an electronic surveillance of that aggrieved person pursuant to the authority of this subchapter[.]” 50 U.S.C. § 1806(c); see id. §§ 1825(d) (physical search), 1845(c) (pen register and trap-and-trace surveillance); 1881e(a)(1) (FAA).16 According to the Senate Judiciary Committee Report accompanying FISA, Congress was aware that it was “depart[ing] from traditional Fourth Amendment criminal procedures,” but it concluded that the “need to preserve secrecy for sensitive counterintelligence sources and methods justifies elimination” of the “requirement of subsequent notice to the surveillance target ... unless the fruits are to be used against him in legal proceedings” S. Rep. No. 95-701, at 11–12 (1978) (emphasis added).

At a minimum, then, the Fourth Amendment requires notice to a criminal defendant when the prosecution intends to enter into evidence or otherwise use or disclose information obtained or derived from surveillance of that defendant conducted pursuant to the government’s foreign intelligence authorities. See Dalia, 441 U.S. at 248; Berger, 388 U.S. at 60.

This constitutional notice requirement applies to surveillance conducted under FISA and the FAA, which codify the requirement with respect to several types of surveillance. 50 U.S.C. §§ 1806(c), 1825(d), 1845(c), 1881e(a)(1). It also applies to surveillance conducted under other foreign intelligence authorities, including Executive Order 12,333 and the FAA’s predecessor programs. Indeed, the notice requirement is of particular importance with regard to these latter, non-statutory programs precisely because these programs lack the statutory protections included in FISA. Where statutory protections are lacking, the Fourth Amendment’s reasonableness requirement takes on importance as a limit on executive power, and notice is necessary so that criminal defendants may challenge surveillance as inconsistent with that requirement.

We emphasize that notice is distinct from disclosure. Given the need for secrecy in the foreign intelligence context, the government is required only to inform the defendant that surveillance occurred and that the government intends to use information obtained or derived from it. Knowledge of surveillance will enable the defendant to file a motion with the district court challenging its legality. If the government avers that disclosure of information relating to the surveillance would harm national security, then the court can review the materials bearing on its legality in camera and ex parte. See, e.g., 50 U.S.C. § 1806(f) (allowing in camera, ex parte review of the legality of electronic surveillance under FISA Subchapter I if “the Attorney General files an affidavit under oath that disclosure or an adversary hearing would harm the national security of the United States”).

Reflections on What This Might Mean

This is super interesting, and potentially quite important.

This strikes me as a very different kind of constitutional notice requirement than what courts have recognized before. In past cases, the constitutional notice requirement was designed to leave notice where a warrant was executed, or to people who were searched with a warrant, regardless of whether criminal charges were filed. This notice rule seems pretty different. This is a notice rule that is all about making the exclusionary rule meaningful. You don’t get notice unless you are criminally charged, and the notice you get is designed to alert you that you might have a plausible motion to suppress that you should look into and consider filing.

And not only does it not require a warrant, it doesn’t even seem to require a search. The notice seems to be that evidence was obtained using a surveillance authority. It doesn’t appear to require that this authority is anything that has been understood to involve Fourth Amendment searches or seizures. Rather, the notice is provided so a person can bring a challenge and argue to a court that it’s a search or seizure, and an unreasonable search or seizure at that.

Put another way, this appears to be a Fourth Amendment notice requirement to alert criminal defendants that the government took steps that might constitute a search—but also might turn out not to be a search at all once a court reviews the matter closely. It has faint echoes to me of Miranda v. Arizona, in that it’s a judicially created notice about your rights potentially at stake so that you can take action to vindicate your rights.

Is it possible to read the opinion more narrowly? I think so, but it’s a little complicated. As I see it, the opinion seems to more or less follow this syllogism: (a) There is a Fourth Amendment notice requirement in ordinary criminal cases; (b) Congress has enacted a statutory notice requirement like this one for other national security surveillance programs that the 1978 legislative history explains as a national security version of the ordinary Fourth Amendment notice requirement; and therefore (c) the statutory requirement is a constitutional requirement in national security cases where Congress for some reason forgot to include it. If you accept this syllogism, it’s not obvious that the court is aware of how potentially pathbreaking its position may be.

My difficulty with predicting Moalin’s significance is that I think both of the syllogism’s premises are mistaken. Given that, it’s not entirely clear where the decision’s reasoning will take courts in the future. As to (a), the Fourth Amendment notice requirement traditionally has been only for warrants. And as to (b), the legislative history articulating the Fourth Amendment notice requirement for national security cases was also only about warrants. It’s legislative history from the original 1978 FISA law that only had warrant authorities, not from the decades-later amendments that added nonwarrant authorities such as pen registers and bulk orders. The fact that Congress later extended similar statutory notice requirements outside the warrant context doesn’t provide a significant basis for constitutionalizing that notice requirement when a warrant is not involved.

Where Moalin goes depends on which parts of the syllogism other courts will accept going forward, if any. If you wanted to construe Moalin narrowly, for example, I suppose you could try to focus on (b) and limit Moalin to national security cases, arguing that the notice requirement of (a) is still limited to warrant cases. Perhaps you could then argue that there isn’t a similar need for warrantless notice outside the national security context.

If you fully accept the syllogism, however, Moalin may have a major impact outside the national security context. The court is taking a major step by imposing a constitutional notice requirement outside the warrant setting, and even potentially outside the search setting. If that notice requirement applies outside the national security setting, it could mark a major change in practice.

For example, let’s say the government makes a preservation request under 18 U.S.C. § 2703(f), asking a provider to preserve the contents of an email account belonging to the target of a criminal case before the government compels its disclosure with a warrant. Under Moalin, does the government have to provide notice of the § 2703(f) request so the defendant can challenge that procedure? I have argued that the § 2703(f) procedure raises major constitutional difficulties, and the use of § 2703(f) requests is normally not disclosed by default. Is it now a constitutional requirement that the preservation request be disclosed?

Or let’s say that the government used an automated license plate reader (ALPR) to locate the suspect at some point. Under Moalin, does the government have to provide notice that an ALPR was used? Or perhaps the government monitored the suspect’s power bills, or observed the suspect using pole cameras, or took other steps that may or may not be a search under Carpenter v. United States. Does the notice requirement apply?

To be clear, I’m not necessarily complaining if the answer is yes. From a policy perspective, these sorts of notice requirements strike me as a good thing, at least if they are implemented appropriately (more on this below). As Judge Berzon notes, notice can help defendants vindicate constitutional rights. And from a law nerd perspective, notice can help generate cases that clarify the law one way or the other. So that’s all to the good from a policy perspective. But from a constitutional perspective, I wonder how solid the ground is here and how far it goes.

This brings me to my last point. There are lots of questions to be answered if this notice requirement extends to the criminal warrantless context. After all, it’s easy to know what a notice requirement means with a warrant: A place or a person was searched under the warrant, and the notice is of that. But it’s a lot harder to know what to make of a notice requirement outside the warrant context.

For example, when is the requirement triggered? In the criminal context, is it triggered after the possible search occurred, rather than when charges are brought? What kind of practices does it cover? If it covers conduct that may or may not be a search, how significant a prospect that the conduct was a search is required to provide the notice? Does the application of that rule change over time, as case law may change on what is a search?

And what are remedies for the notice violation? In the warrant setting, notice is part of reasonableness. But if there was no notice of a surveillance program that ends up not being a search, can there be a Fourth Amendment notice violation without a search or seizure occurring? Can there be an unreasonable nonsearch that violates the Fourth Amendment? And say the government fails to give notice and the defendant thus fails to make a challenge, only to learn later that he could have made a plausible challenge had the required notice been given. Can he challenge the conviction in some sort of collateral attack, perhaps getting a new suppression hearing, sort of like a Jackson v. Denno hearing but under the Fourth Amendment?

Lots of fascinating stuff here, I think. As always, stay tuned.

Orin Kerr is a Professor at the University of California, Berkeley School of Law. He is a nationally recognized scholar of criminal procedure and computer crime law. Before becoming a law professor, Kerr was a trial attorney in the Computer Crime and Intellectual Property Section at the Department of Justice and a Special Assistant U.S. Attorney in the Eastern District of Virginia. He is a former law clerk for Justice Anthony M. Kennedy of the U.S. Supreme Court and Judge Leonard I. Garth of the U.S. Court of Appeals for the Third Circuit.

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