The Fourth Amendment and General Law.

• Author: D'Onfro, Danielle

ARTICLE CONTENTS INTRODUCTION 913 1. THE ASCENT OF POSITIVE LAW 920 A. The Katz Era 920 B. The Rise of a Positive-Law Approach 922 C. Unanswered Questions 926 II. THE GENERAL-LAW APPROACH 927 A. Understanding General Law 927 B. The General-Law Approach and How It Works 932 C. Justifying the General-Law Approach 936 1. Text, Original Meaning, and History 937 2. Precedent 945 3. The Normative Case 950 a. Fourth Amendment Values 950 b. Flexibility and Constraint 953 III. APPLYING THE GENERAL-LAW APPROACH 955 A. Trespass 956 1. The Scope of the Right to Exclude 957 2. Delegating the Right to Exclude 963 B. Abandonment 965 1. Chattels 965 2. Real Property 968 3. Intangibles 970 C. Bailments 971 1. Tangibles 972 2. Intangibles 977 D. Privacy Torts 979 1. Intrusion on Seclusion 980 2. Public Disclosure of Private Facts 984 3. Breach of Confidentiality 987 E. Additional Issues 987 1. Seizures of the Person 987 2. The Role of Warrants 989 3. Racialized Policing 991 CONCLUSION 992 INTRODUCTION

The modern era of Fourth Amendment jurisprudence began in 1967 with Katz v. United States. (1) That case, and especially Justice Harlan's concurrence, (2) heralded a new approach in which the Amendment's protections turned on "reasonable expectations of privacy." (3) In the decades since, the Supreme Court has used this approach to build a grand edifice of Fourth Amendment doctrine. But now, just over half a century later, the Katz era could be nearing its end. Recent cases have revealed interest among some originalist Justices in restoring a supposed pre-Katz regime under which Fourth Amendment protections turn on concepts of property and trespass rather than amorphous notions of privacy. (4) Aided by scholarly efforts, (5) and perhaps by recent changes in the Court's membership, some kind of "positive law" approach might be poised to flourish.

Yet, Justices drawn to a positive-law approach must still resolve fundamental questions about what exactly that approach would entail. The leading scholarly proponents of a positive-law approach, William Baude and James Y. Stern, argue that in determining questions of the Fourth Amendment's scope, courts should ask whether "the government actor [has] done something that would be tortious, criminal, or otherwise a violation of some legal duty" under positive law if performed by a private persona But the Justices who are receptive to positivelaw arguments have not yet endorsed Baude and Stern's theory, which we might call the "pure" positive-law model. Notably, in his dissent in Carpenter v. United States, (7) Justice Gorsuch stressed his uncertainty about several matters:

[I]f a house, paper, or effect is yours, you have a Fourth Amendment interest in its protection. But what kind of legal interest is sufficient to make something yours? And what source of law determines that? Current positive law? The common law at 1791, extended by analogy to modern times? Both? (8) To Justice Gorsuch's last question, this Article offers a different answer: neither. The Fourth Amendment should not be read as freezing specific commonlaw rules from the Founding Era in constitutional amber. (9) Nor should it be understood as making Fourth Amendment protections wholly dependent on today's positive law--that is, on whether the relevant jurisdiction in which a search or seizure occurs prohibits the conduct at issue for private parties. Instead, courts should interpret the Fourth Amendment by turning to general law. The general law, in Caleb Nelson's words, is a set of "rules that are not under the control of any single jurisdiction, but instead reflect principles or practices common to many different jurisdictions." (10) In other words, this approach would ask courts to resolve Fourth Amendment questions not by looking to the common law of 1791, but instead by using the tools of the common law to determine the general law of the country today.

What would this approach look like in practice? A court would begin by verifying whether the government conduct at issue was a "search" or a "seizure." Under some approaches, this threshold question is complex. For example, under Katz, government conduct is only a "search" if a court concludes that it violates someone's reasonable expectations of privacy. Similarly, under Baude and Stern's model, government only "searches" or "seizes" when it violates the positive law. Under the general-law approach, by contrast, "search" and "seizure" are read in a broader and more commonsense way." The general-law reading accords with the plain meaning of those words themselves and clarifies how the Amendment's clauses interact.

Assuming that the government conduct qualified as a search or seizure, a court would then inquire whether it intruded on someone's "person[], house[], papers, or effects." (12) In many cases, this inquiry is easy: when police barge into someone's home or physically restrain someone, there is little doubt that the Amendment's protections apply. But other questions are harder: can an overnight guest be said to be in her own "house" if the home is searched while she is staying there? Is a digital copy of an email that resides on a cloud-storage company's servers the "papers" of a suspect? (13) Is a homeowner's trash left at the curb that person's "effects"? (14) Courts would answer these questions by looking to well-established general-law property concepts.

If the search or seizure did intrude on one of the Fourth Amendment's protected categories, a court would then determine whether it was "unreasonable" by asking whether it would violate the general law. In this analysis, courts would no longer make untethered and speculative inquiries into "reasonable expectations of privacy," as the Katz test requires (though it confusingly does so at the threshold step of determining whether a "search" occurred). But neither would courts ask whether common-law jurists in 1791 would have seen the government conduct as unlawful. Instead, they would use the tools of the common law, particularly the private law, to aid in determining how the general law would resolve the question today. To be sure, musty property-law concepts like licenses, bailments, and abandonment can help to resolve many hard Fourth Amendment questions. But in determining what searches were "unreasonable," courts would not be limited to the specific common-law rules, or even to the broader commonlaw categories, known when the Fourth Amendment was ratified. Instead, judges would look to how common-law rules have evolved since the Founding. And, in so doing, judges would also contribute to that continued evolution.

Unlike the pure positive-law model, the general-law approach would not treat any one jurisdiction's law governing private parties as controlling. Instead, in trying to identify the country's general law, courts would look to the laws and practices of different jurisdictions as relevant data points--persuasive precedent--not as dispositive authorities. That is, the inquiry would be distinct from the way that federal courts approach questions of state common law governed by Erie Railroad Co. v. Tompkins, under which a particular state's law dictates the rule of decision for a federal court. (15) This is because questions of the Fourth Amendment's scope and protections are best understood as matters of general law rather than "local common law." (16)

In fleshing out the general law, courts would apply the common-law method to new scenarios, just as early twentieth-century courts did in recognizing new privacy-based torts for the modern commercial era. If a court identified a right recognized by the general law that the government might have infringed, it would ask what protections the general law would extend to that right. For example, if an overnight guest is a licensee under general law, (17) are such licensees protected against nonconsensual intrusions? (18) If a cloud-storage company is best understood as a bailee of a person's data, (19) then what protections should the law of bailment provide the bailor to guarantee her security over her belongings? And under the ad coelum doctrine, (20) should a homeowner have the right to exclude others from flying a drone forty feet above her backyard? (21)

Sometimes existing common-law case law will reveal a well-developed consensus about whether a particular right exists and what protections it deserves. At other times, especially in situations involving emerging technologies, a court will have much less to draw on. But a court in such a position is no worse off than any common-law court (or, for that matter, a court applying the Katz framework) confronting a novel factual scenario. Just as common-law courts have applied the common-law framework to new fact patterns for centuries, so would courts interpreting the Fourth Amendment using a general-law approach.

If a court concluded that a search or seizure did violate a claimant's rights under the general law, the search will be presumptively unlawful if government actors did not obtain a warrant in advance. Current doctrine speaks of a warrant "requirement" and its "exceptions." (22) But the better way to read the Fourth Amendment's text--one more consistent with its historical background--is that a proper warrant immunizes otherwise unlawful conduct. In most contexts where current doctrine sees an "exception" to the supposed warrant requirement, the better understanding is that the government conduct simply does not violate the general law in the first place--and thus is not "unreasonable"--for reasons rooted in traditional general-law principles.

The general-law approach has many advantages over its competitors. Some are pragmatic: it is more straightforward to apply and produces more attractive results. Moreover, unlike the dominant Katz approach, it also gives courts a firmer foundation upon which to build doctrine than judges' own intuitions about privacy expectations.

But it is also...