Author:Bellin, Jeffrey

The Fourth Amendment's prohibition of "unreasonable searches" is one of the most storied constitutional commands. Yet after decades of Supreme Court jurisprudence, a coherent definition of the term "search" remains surprisingly elusive. Even the justices know they have a problem. Recent opinions only halfheartedly apply the controlling "reasonable expectation of privacy" test and its wildly unpopular cousin, "third-party doctrine," with a few justices in open revolt.

These fissures hint at the Court's openness to a new approach. Unfortunately, no viable alternatives appear on the horizon. The justices themselves offer little in the way of a replacement. And scholars' proposals exhibit the same complexity, subjectivity, and illegitimacy that pervade the status quo.

This Article proposes a shift toward simplicity. Buried underneath the doctrinal complexity of the past fifty years is a straightforward constitutional directive. A three-part formula, derived from the constitutional text, deftly solves the Fourth Amendment "search" conundrums that continue to beguile the Court. This textualist approach offers clarity and legitimacy, both long missing from "search" jurisprudence. And by generating predictable and sensible answers, the proposed framework establishes clear boundaries for police investigation while incentivizing legislators to add additional privacy protections where needed.

INTRODUCTION I. A SHORT HISTORY OF THE CURRENT PREDICAMENT A. The Pre-Katz Era's Casual Textualism B. Katz and the "Reasonable Expectation of Privacy" Test C. Post-Katz Textual Drift II. A Return to the Fourth Amendment's Text A. Defining "Search" B. "Persons, Houses, Papers" C. "And Effects" D. "Their" Replaces Third-Party Doctrine and Standing III. APPLYING AN OLD TEXT TO NEW TECHNOLOGIES A. Searches of Persons B. Public Surveillance and Tracking C. Intercepting Electronic Signals and the Internet of Things CONCLUSION INTRODUCTION

"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated...."

--United States Constitution, Amendment IV

The Fourth Amendment prohibits unreasonable "searches" and "seizures." This places the Supreme Court's definition of the term "search" at the center of the always-evolving balance between privacy and security. Technological advances offer the government a steady stream of novel investigative techniques, but only those that qualify as "searches" (or "seizures" (1)) trigger Fourth Amendment protections. (2)

Ever since the 1967 case Katz v. United States, the Supreme Court has framed the "is-it-a-search?" inquiry by asking whether the police invaded the complaining party's "reasonable expectation of privacy." (3) Scholarly commentary on this doctrine kills more trees than termites. Yet despite all the attention, the "reasonable expectation of privacy" test remains "the central mystery of Fourth Amendment law"; "no one seems to know what makes an expectation of privacy constitutionally 'reasonable.'" (4)

The Katz test's indeterminacy was on display in the Supreme Court's latest Fourth Amendment "blockbuster." (5) In Carpenter v. United States, police obtained records containing "cell-site location information (CSLI)" from two wireless carriers. (6) The records revealed Timothy Carpenter's location in the vicinity of a series of robberies in downtown Detroit. (7) Precedent suggested this was not a "search." The Supreme Court had previously held that there was no reasonable expectation of privacy in (1) information obtained from third parties (8) or (2) one's location in public areas. (9) Highlighting "the unique nature of cell phone location information," however, the Court ruled (5-4) that the government "invaded Carpenter's reasonable expectation of privacy." (10) Consequently, "accessing seven days of CSLI constitutes a Fourth Amendment search." (11) No principle emerges from the opinion (seven days?), or the laundry list of related scenarios where the Court cautioned that its analysis might not apply. (12) Instead, the justices in the majority emphasized the need to "tread carefully" to "ensure that we do not 'embarrass the future.' " (13) The present gets no such reprieve.

The irony of the Supreme Court's modern "search" jurisprudence is that the "reasonable expectation of privacy" test was supposed to avoid making "a crazy quilt of the Fourth Amendment." (14) And yet here we are: "[A] fourth amendment with all of the character and consistency of a Rorschach blot." (15) Extending the trendline into the future, there will be a line of cases for each "unique" technology and product: cell phones, GPS tracking, facial recognition, license plate readers, Alexa, Fitbit, and on and on. Reasoning by decree in a case or two each year, the Court will label applications of some technologies "searches," leave others unrestricted as "non-searches," and never opine on the rest. For the vast majority of potential search scenarios (six days of cell-site location information?), lower courts, citizens, and the police will be left guessing about what the Constitution permits. (16)

Despite its widely recognized indeterminacy, the "reasonable expectation of privacy" test endures. The best explanation for its longevity is a lack of viable alternatives. (17) Judges and scholars rarely posit new formulations for defining a Fourth Amendment "search." Instead, reform proposals generally accept the Katz formula as an "inevitable first step in the direction of administrability" (18) and seek to either cleanse the analysis of its perceived failings (19) or incorporate new factors. (20) Some scholars advocate making the Katz test even more pliable so the Court can focus on the central policy question, "how best to regulate government information gathering." (21) The few efforts to dispense with Katz, like a recent proposal that ties searches and seizures to violations of "positive law," (22) promise as much complexity and uncertainty as Katz itself. (23) In the end, these alternatives all suffer from similar flaws. They are too complex, too subjective, too incomplete, and too far removed from the Amendment's text to improve on the status quo. There is little to be gained by further tinkering with Katz or exchanging the "reasonable expectation" formula for another shiny but impenetrable framework. Fortunately, there is another option.

This Article proposes a simple alternative to the Supreme Court's Fourth Amendment "search" jurisprudence: a return to the constitutional text. Step one is to scrap Katz's "reasonable expectation of privacy" test as an unmitigated failure of constitutional interpretation, both incoherent and illegitimate. Step two is to adopt a straightforward methodology, "Fourth Amendment Textualism," which derives a comprehensive "search" jurisprudence from three components of the Fourth Amendment's text. (24) The proposal's defining theme is simplicity. If the Supreme Court can muster the will to cast aside the artificial complexity of the past fifty years, it will uncover a straightforward textual command. All the Court needs is a dictionary, a touch of history, and some common sense.

The proposal begins with the word "search." The term at the center of this morass is a common one, with an intuitive meaning supported by a clear historical imperative. There is no indication in the historical record or the pre-Katz case law that the Fourth Amendment's specification of "searches" as an event of constitutional interest was intended to be so inscrutable. (25) A definition can come in handy for difficult cases, but will typically be unnecessary. A "search" is an examination of an object or space to uncover information. (26) But you knew that already. The police search houses, pockets, papers, and cars. They also search electronic documents and devices by reading and scanning them for information. Importantly, while all searches seek to uncover information, not all information gathering qualifies as a search. Police do not "search" when they ask suspects or witnesses questions, ponder unsolved cases, or rearrange data already in their possession. (27) In sum, a "search" is a search. (28) It may be impossible to craft "a single test for when an expectation of privacy is reasonable." (29) But, as I hope to show, it is not nearly so difficult to define the term "search." (30)

Next, a textualist approach reintroduces the often overlooked fact that the Fourth Amendment does not target all "searches." The only searches that count for Fourth Amendment purposes are searches of "persons, houses, papers, and effects." (31) Why? It says so in the Fourth Amendment. The Amendment's enumeration of these "constitutionally protected areas"--a legal phrase once in vogue but largely abandoned after Katz (32)--buttresses the sense that Fourth Amendment "searches" target tangible objects or spaces and further clarifies the Amendment's scope.

As a result of the "persons, houses, papers, and effects" limit, many investigative techniques that satisfy a commonsense definition of "search" should not trigger Fourth Amendment protections. For example, restrictions on public surveillance must be left to the legislature. Visual and audio surveillance of public streets and parks might constitute a search, but not a search of a "person," "paper," "house," or "effect." (As I will explain, there is a subtle, but inescapable, textual distinction between searching a person and searching for a person.) (33) Importantly for this analysis--and as explained in detail below--intangible items like a person's voice, image, or cell phone signals do not constitute "effects" under any plausible interpretation of the term. (34)

There is one more piece. A Fourth Amendment textualist can jettison all of the baggage that comes along with Katz, including "third-party doctrine": the much-maligned rule that holds that "a person has no legitimate expectation of...

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