A man talks on an iPhone at a subway stop in Manhattan in 2011. (Shannon Stapleton/Reuters)

The Roberts Court has missed chances to roll back judicial activism on privacy.

Editor’s Note: The following is the tenth in a series of articles in which Mr. Yoo and Mr. Phillips lay out a course of constitutional restoration, pointing out areas where the Supreme Court has driven the Constitution off its rails and the ways the current Court can put it back on track. The first entry is available here, the second here, the third here, the fourth here, the fifth here, the sixth here, the seventh here, the eighth here, and the ninth here.


We close our series on the new Roberts Court and restoration of the Constitution’s original understanding with the issue most distant from the Framing: the rise of a new high-tech world. We now hold the equivalent of yesterday’s supercomputers in our pockets. Communications occur instantly, from encrypted messages to Twitter blasts that reach millions. Entrepreneurs make fortunes by analyzing and harvesting the 2.5 quintillion bytes of data produced each day. Governments search the data to find terrorist networks or launch foreign propaganda. From business to politics, success depends on reading the tea leaves we electronically leave behind with social-media posts, texts and emails, or Google searches.

As inevitably as the weather, the hand of regulation has followed. While using the data for itself, the state seeks to regulate the businesses and individuals that create it. We have only begun to figure out whether the rules of privacy that governed paper records, telephone calls, and the mails will continue to apply, and how, to emails, texts, video clips, and social media. Not only does technology create more data that individuals want to protect; it also expands the government’s ability to search and manipulate. Where the line will fall between new technologies, regulation, and privacy will likely become the greatest legacy of Chief Justice John Roberts’s Supreme Court.

The Court will have the opportunity to correct the mistakes of its past. In the 1950s and ’60s, the Supreme Court under Chief Justice Earl Warren sought to adapt constitutional rules to electronic technologies such as the telephone. The liberal Warren Court ignored the Bill of Rights’ text and original meaning as part of a broader effort to remake the criminal procedure of the Constitution in its own image. We may again be facing a similar revolution, not out of fear of police and prosecutors, but out of unfounded worries about a Big Brother government. How the Roberts Court handles these coming issues will reveal much about how originalist the Court actually is.

In an ideal world, we might expect the political process to make the fundamental choices about the balance between privacy, government power, and the new communication and information technologies. But ever since the Warren Court, the Supreme Court has claimed that the Fourth Amendment gives it a right to set the rules. The text of the Fourth Amendment states:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Scholars and judges generally agree that the Framers of the Fourth Amendment sought to prevent general warrants, which officers of the British Crown had used to search American colonists at any time, for any reason. But during the Warren years, the Justices transformed this ban into a requirement that the government could not conduct a constitutional search without a Fourth Amendment warrant based on probable cause, with a specific description of the persons and places to be searched. In Mapp v. Ohio (1961), the Warren Court extended the notorious exclusionary rule, which excludes from trial any evidence gathered in violation of the Fourth Amendment to all courtrooms throughout the nation. As even the liberal justice Benjamin Cardozo had complained as early as 1926, “the criminal is to go free because the constable has blundered.”

This general rule flies in the face of the text of the Fourth Amendment. Instead of assuming that only searches with warrants satisfy the Constitution, we ought to understand the amendment as composed of two parts: the search-and-seizures clause and the warrants clause. The text of the amendment fundamentally requires reasonable searches. If a search or seizure were reasonable, in the ordinary meaning of the word, then it would be legal, regardless of whether a specific warrant had been issued. Why then the warrant requirement? Such a requirement makes sense if the Framers considered search or seizure supported by a specific, judge-issued warrant to be per se reasonable. A warrant protected constables from lawsuits that, while more common during the Founding, have largely disappeared because of the Court’s immunity doctrines. The amendment recognizes two paths to reasonable, and thus legal, searches and seizures.


To be sure, some originalists defend the Warren Court, in part. They observe that the Pennsylvania and Massachusetts state constitutions contained nearly identical language, with one minor but clarifying difference: The relationship between the two clauses was not an “and” but a “therefore.” This difference would suggest that a specific warrant and reasonableness were one and the same. Further, according to this view, “unreasonable” meant against reason, which meant against the common law. And under the common law at the Founding, a warrant was necessary for a search or seizure unless law enforcement caught someone in the act of committing a felony.


Even if this reading of the Fourth Amendment were correct, the Warren Court made no attempt to base its policymaking on the amendment’s original meaning. Instead, it eagerly sought to impose a regime of judicial supervision over virtually all government searches, even over technologies that would have appeared to be magic to the Framers. No case exemplifies the Court’s approach better than Katz v. United States (1967). In Katz, the Warren Court found that the Fourth Amendment required a warrant to allow the police to place a listening device in a public phone booth. The defendant had used the phone in a public place outside his house, and his call was electronically intangible — the Fourth Amendment protects only tangible things: “persons, houses, papers, and effects.” But the Court found that his conversation fell within a “reasonable expectation of privacy” that was recognized by society. Rather than allowing Congress and the states to decide how much protection to give phone calls or any other electronic means of communication, the justices took for themselves the power to decide what would qualify as privacy.


As they did in other areas we have already examined, the justices assumed the roles of philosopher-kings. How do courts know that society views an expectation of privacy as objectively reasonable? According to Katz, they just do. How will courts determine what society thinks? Opinion polls? And why does the Fourth Amendment expand or contract depending on what society thinks should be private? Katz’s definition of privacy fails not only because judges cannot determine society’s view on privacy (that is, after all, the job of legislatures), but because it is utterly circular. Instead of providing any certainty with clear rules, the federal courts turned themselves into the arbiters of privacy, the definers of the legal scope of every new technology, and the monitors of all police investigations.


Under Chief Justice William Rehnquist, and majorities formed by Reagan and Bush judges, the Supreme Court tried to pare back the Warren Court’s activism. The Rehnquist Court created exceptions for searches conducted under exigent circumstances (such as evidence found while pursuing fleeing felons or protecting the lives of others), in good faith (such as operating under a defective warrant), at random (such as random drug-testing and drunk-driver checkpoints), or in plain view (public spaces, observation on the street). In these decisions, the Rehnquist Court began to recognize that while searches with a warrant were reasonable, not all reasonable searches need a warrant. Some observers believed that the Rehnquist Court might even overturn the exclusionary rule or Katz, but it never took that controversial step.

One of the chief surprises of the Roberts Court is that the justices have turned away from their predecessors’ project of restoring reasonableness as the constitutional touchstone. When faced with the new technologies, a majority of justices have ignored the original understanding of the Fourth Amendment and reverted to the Warren Court’s free-floating approach to privacy and government search. They have placed significant restrictions on the government’s use of new technology for policing and anti-terrorism operations, even as foreign nations escalate their use of cyber weapons to steal valuable data (such as the security and background files of almost every federal employee), hack infrastructure, and interfere with elections. The Court has precipitously plunged into the complexities of technology and privacy, where its competence is not high, instead of allowing the people’s elected representatives to make the fundamental choices.


The early signs of this high-tech activism first emerged under the Rehnquist Court. In Kyllo v. United States (2001), the Court confronted a case where a Department of Interior officer had used a new technology to search for indoor marijuana growers. The officer used a thermal imaging device that could measure the heat emitted by a building, but did not allow agents to see or listen to the activity within the house. In an opinion written by Justice Scalia, an unusual majority composed of Clarence Thomas, David Souter, Ruth Bader Ginsburg, and Stephen Breyer held that the Fourth Amendment prohibited the search, even though past opinions had found that evidence in plain view or in public outside the home did not require a warrant before search. “We think that obtaining by sense-enhancing technology any information regarding the interior of the home that could not otherwise have been obtained without physical ‘intrusion into a constitutionally protected area,’” Scalia wrote, “constitutes a search at least where (as here) the technology in question is not in general public use.” According to the majority, “this assures preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” The dissent properly observed that the officer observed something outside the house, much as an officer might hear screams coming from within or witness smoke pouring from a window. But unfortunately, the Court thought it should set the standard for advanced sensor technology, rather than allowing the elected branches to decide — either Congress through legislation or the executive branch via regulation.

Despite its conservative reputation, the Roberts Court picked up where the Rehnquist Court’s Kyllo decision left off. In United States v. Jones (2012), the Court addressed police use of a device that used the Global Positioning System to track a car’s movements. Without getting a warrant, Washington, D.C., police attached a device to a suspected drug dealer’s Jeep that reported its movements 24 hours a day for a month. Writing for the majority, Justice Scalia held that the placement of the device constituted a physical invasion of the car. All of the justices agreed that the GPS monitoring device violated the Fourth Amendment, though some justices believed that shorter time periods might satisfy the Constitution. But the Court’s decision did not persuasively address why the GPS device amounted to an illegal search, while the exact same work conducted by human beings – having police officers conduct round-the-clock surveillance – would not violate the Constitution. In both cases, the tracker or the police officer simply follows the public movements of a suspect’s car. The tracking device only saves time and resources, and even intrudes less on privacy because it would observe only the location of the car and not what happened inside. The Court’s approach only invites more intrusive surveillance, such as deploying an aerial drone, which would never come into physical contact with the car, or even need to use enhanced sensors, to follow a suspect and report its movements instead. It is difficult to believe that the justices would forbid the police the use of night vision, in the way they forbade GPS, in public places to pursue fleeing felons. Police could simply follow a car when it travels on public roads and record video of its movements in real time.


The Roberts Court’s most recent opinion, Carpenter v. United States (2018), might prove its most sweeping. In a 5–4 decision, the chief justice joined the Court’s four liberals in finding that a person had an expectation of privacy in records kept by a telephone company of his cellphone’s location. Dissenting Justices Kennedy, Thomas, Alito, and Gorsuch argued that the third-party exception to the Fourth Amendment meant no warrant was required. Under existing doctrine, and the plain text of the amendment, individuals lose their claim to privacy over records or information that they willingly hand over to a third party. Upon this understanding, the Court has allowed warrantless searches such as “pen registers,” which record dialed telephone numbers, and for business records such as credit-card and financial transactions, because the original owner voluntarily gave the information to someone else. In this case, the owner of the cellphone allows the device to constantly “ping” the wireless cellphone network, which notifies the telephone company of its location. Police used the information to show that the suspects — who had, ironically, sought to rob cellphone stores — were present at the time and place of a series of crimes.


Nevertheless, the Court held that such nonprivate information received the protections of the Fourth Amendment. The Court did not find that the means to gather the information violated the text of the Constitution, but that somehow the data violated the Fourth Amendment because the government had come to have too much information. Chief Justice Roberts concluded that such commercial records still fell within the suspect’s “anticipation of privacy in his physical location” because “the time-stamped data provides an intimate window into a person’s life,” not just now, but well into the past. The problem with Chief Justice Roberts’s approach is that it provides no clear rule about how much information is too much information for the government to have, how courts and police are to decide, or why the Fourth Amendment even places limits on how much knowledge the government can have about its citizens’ public activities. Chief Justice Roberts, for example, might believe that the Fourth Amendment would bar government agencies from examining social media, even though individuals choose to blog and post so that many people can see, or financial data, which we transmit to banks and companies. He inevitably “invites courts to make judgments about policy, not law,” as Justice Thomas wrote in dissent.

These cases demonstrate that the Court, though now composed of a conservative majority appointed by Republican presidents, may still drift in a liberal direction. It is most likely to do so when, as here, it leaves behind the constitutional text and history in favor of judgments — no matter how reasonable or popular — that fall within the province of the elected branches of government. Technological advances will continue to pressure the Court to get creative with the Constitution over the intersection of privacy and law enforcement. So the justices have a choice. They can tread the constitutionally dubious path laid out by the Warren Court and invent whatever doctrine or test they think will be optimal from a policy perspective, per Katz and Carpenter.

Or they can leave that to the nation’s policymakers: Congress and the president. There is precedent for the elected branches making decisions related to the intersection of privacy and law enforcement. In 1968, Congress passed the Omnibus Crime Control and Safe Streets Act, in part as a response to Katz, which was handed down just a year earlier. The act allowed the institution best able to weigh the competing policy interests of privacy and safety — the legislature — to make the balancing determination. The Constitution’s federal structure also encourages states to experiment with different balances of privacy and security. Of course, the text and history of the Constitution provide a floor. But if society wishes to provide greater protection for privacy at the cost of some security, it should make that decision through the same political process that it uses for other public policies.

As technological development continues to accelerate, the Court will have a decision to make. Will it usurp the authority of the people and their representatives to decide how to best move forward in this new world, or will it succumb to the temptation of playing platonic guardians who know better how to navigate the future? Time will tell which path the Court chooses, but the Constitution has an answer, if they choose to consult it.