Digital Searches, the Fourth Amendment, and the Magistrates' Revolt

• Publication year: 2018

Digital Searches, the Fourth Amendment, and the Magistrates' Revolt

Emily Berman

DIGITAL SEARCHES, THE FOURTH AMENDMENT, AND THE MAGISTRATES' REVOLT

Emily Berman^*

ABSTRACT

Searches of electronically stored information present a Fourth Amendment challenge. It is often impossible for investigators to identify and collect, at the time a warrant is executed, only the specific data whose seizure is authorized. Instead, the government must seize the entire storage medium—e.g., a hard drive or a cell phone—and extract responsive information later. But investigators conducting that subsequent search inevitably will encounter vast amounts of non-responsive (and often intensely personal) information contained on the device. The challenge thus becomes how to balance the resulting privacy concerns with law enforcement's legitimate need to investigate crime. Some magistrate judges have begun including in their warrants for digital searches limits on how those searches may be carried out—a development that some have referred to as a "magistrates' revolt," and which has both supporters and detractors. This Article argues that the magistrates' "revolt" was actually no revolt at all. Instead, these judges simply adopted a time-honored tool— minimization—that is used to address a conceptually analogous privacy threat posed by foreign intelligence collection. This Article further argues that embracing both the practice and the label of "minimization" will yield at least two benefits: First, it will recast magistrates' actions as a new instantiation of a legitimate judicial role, rather than a novel, potentially illegitimate practice. Second, it will allow magistrates to draw on lessons learned from the Foreign Intelligence Surveillance Court's creative use of minimization to safeguard Fourth Amendment rights in the intelligence-collection context.

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INTRODUCTION...............................................................................................51

I. Digital Searches and the Fourth Amendment..........................57

A. Digital Searches and the Fourth Amendment............................. 57
B. The Magistrates' Revolt ............................................................. 61

II. Minimization Procedures: Congress's Response to Inevitable Over-Collection.............................................................................66

A. The Origins of Minimization Procedures ................................... 67
B. The Implementation of Minimization Procedures ...................... 71

1. Minimization in Criminal Investigations.............................. 71
2. Minimization in Foreign Intelligence Surveillance .............. 72

a. "Traditional" FISA ....................................................... 73
b. The FISA Amendments Act: PRISM............................... 74
c. The FISA Amendments Act: "Upstream" Collection .... 76
d. Metadata Collection ...................................................... 78

III. Minimization Procedures: Mitigating Privacy Concerns in Digital Searches.............................................................................82

A. Minimization's Untapped Potential ............................................ 82
B. The Advantages of Ex Ante Minimization Over Ex Post Judicial Review ........................................................................................ 86
C. Magistrate Judges' Authority to Require Minimization Procedures.................................................................................. 91

Conclusion...................................................................................................93

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INTRODUCTION

In the 1967 Supreme Court case Berger v. New York, Justice Clark wrote that, "law, though jealous of individual privacy, has not kept pace with . . . advances in scientific knowledge."¹ In the half-century since he wrote those words, the gap between technological advancement and the legal regime has only grown wider. The pace of technological change has accelerated. The role of technology in Americans' daily lives has swelled. Yet even in this twenty-first century world, the speed at which legal change moves remains much as it has been since the eighteenth century.

When it comes to the Fourth Amendment—which protects against unreasonable searches and seizures of our "persons, houses, papers, and effects"—this sluggish pace has proved particularly problematic.² The information age has generated an avalanche of Fourth Amendment-law dilemmas³ —whether the same rules that apply to searching suitcases at the border apply to a traveler's laptop computer;⁴ whether mapping an individual's life 24/7 for days on end using cell phone location records requires a warrant;⁵ whether the results of predictive algorithms generated using massive databases can form the basis of reasonable suspicion;⁶ whether and how the warrant requirement's exception for searches incident to arrest should apply to the contents of an arrestee's cell phone.⁷ It is up to courts in the first instance to resolve these questions.⁸

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Searches and seizures of electronic media, such as computers and smart phones, present judges with a particularly thorny example of this phenomenon. For a traditional analog search or seizure to pass Fourth Amendment muster, the government must (1) apply to a neutral magistrate for a search warrant, (2) satisfy that magistrate that there is probable cause to believe that the search will lead to evidence of a crime, and (3) identify with particularity the places to be searched and the evidence to be seized.⁹ The magistrate then memorializes that information in a warrant, which authorizes law enforcement officials to execute a search of those places and to seize that evidence. These rules are designed to constrain government discretion, ensuring both that law enforcement officials have sufficient justification for infringing on a citizen's privacy and that the infringement is no more significant than necessary.¹⁰

When it comes to digital evidence, however, it is often impossible at the time of seizure to locate and segregate data that is responsive to a warrant from the vast amount of non-responsive (and often intensely personal) data stored on the same device. Imagine, for example, that Harry is suspected of tax fraud, and law enforcement gets a warrant to seize tax-related documents from his home computer. While looking through Harry's computer files for evidence of tax fraud, investigators are likely to come across quite a few non-tax-related files, which could be private items such as personal correspondence or detailed medical information. Similarly, investigators seeking evidence that a computer was used to view child pornography might discover (lawful) intimate photographs or an Internet search history suggesting a substance-abuse problem. In other words, the search might result in exactly the kind of intrusive search that warrants are supposed to prevent.¹¹

Rule 41 of the Federal Rules of Criminal Procedure was amended in 2009 to recognize the unique nature of digital searches and offers as a partial solution a two-step process.¹² First, when it comes to digital searches, investigators may

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engage in an overbroad seizure, such as seizing an entire computer, rather than only those files that contain evidence described in the warrant.¹³ Then, investigators can subject the seized data to "a later review."¹⁴ While this rule may ensure that law enforcement officers can perform a thorough seizure of evidence responsive to the warrant, it does not entirely solve the problem. Whenever the search ultimately takes place, investigators still must identify the evidence—tax returns, for example—and separate it from other non-responsive data, such as private letters. This raises the question of what limits, if any, should govern investigators' access to or use of the non-responsive information it encounters—a question that Rule 41 declines to answer.¹⁵

In an effort to fill this gap, a handful of magistrate judges took matters into their own hands in what has been described in some quarters as a "magistrates' revolt."¹⁶ The "revolt" consisted of a series of opinions issued by federal magistrates around the country that sought to balance the interests of investigators against suspects' privacy rights by rejecting law enforcement's warrant requests for digital evidence unless those requests included (sometimes detailed) ex ante restrictions on how the government would carry out the search, such as limiting how long the government could keep the hardware it seized, specifying how the government would conduct the search, or explaining what the government would do with information it uncovered that fell outside the scope of the warrant.¹⁷ The number of magistrates involved was not large, but the opinions had outsized effect, prompting a debate on the propriety of the practice.

The magistrates' approach has been championed by some commentators as an effective means of addressing the Fourth Amendment challenge posed by digital searches. Professor Paul Ohm argues, for example, that these types of

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restrictions "have become necessary; they are the only way the courts can fulfill their constitutional duty to protect privacy from government overreaching."¹⁸ The highly influential former Ninth Circuit Judge Alex Kozinski also contended that magistrates should include a series of ex ante instructions in the warrants for digital searches that they issue.¹⁹ Indeed, several magistrates' orders considered part of the revolt used Judge Kozinski's suggested framework as a blueprint.²⁰

Yet while it might seem like an elegant means to fill a gap in existing law, the practice has not been universally endorsed. Fourth Amendment expert Professor Orin Kerr has argued, for example, that memorializing ex ante rules for searches of electronic media is neither lawful nor normatively advisable.²¹ Kerr and other opponents of...