The term privacy has a wide range of connotations for libertarians as for scholars generally. In a broad sense, privacy refers to the condition obtained when one’s intimate or personal life is inviolate. In political discourse, libertarians argue, as did the classical liberal theorists who preceded them, that one’s personal life is bounded by property or contract rights. As with other liberties, libertarians are particularly concerned about the government’s singular powers to violate privacy rights, particularly through the use of its police powers. Although a private actor might invade a person’s privacy, libertarian analysis generally treats most such instances as trespasses, whereas the surveillance of workers by their employers is treated under contract law. Thus, for most libertarians, privacy refers to rights threatened by government surveillance or by the abuse of the police powers of search and seizure—types of informational privacy. Using the term more broadly, other state invasions of privacy would include laws against some types of consensual sexual relations between adults, such as prostitution, polygamy, or sodomy. Some libertarians also describe regulation of intimate sexual or family conduct as a privacy issue.

In the realm of informational privacy, threats to privacy emanating from government are essentially of two types. The first involves the state’s misuse of information it has gathered about individuals, whereas the second relates to the misuse of its powers to gather information. An apt example of the first is the use of census data by National Socialists in Germany, Romania, and other countries to identify Jews and other targets of the Holocaust. Census data also were used by the U.S. government to identify Japanese Americans for relocation to concentration camps.

An example of the second is the “general warrant” used by British and Canadian law enforcement between 1662 and 1766 to conduct searches of private homes at any time of the day or night without notice. These warrants also could be used to arrest previously unspecified persons. To control the threat to human rights from the unique powers of government to arrest, try, and imprison members of the public, libertarians have consistently supported strict limits on the powers of government to collect information. Historically, most such limits have been procedural rather than substantive. That is, to the extent that governments submitted to restrictions in this area, the restrictions governed the means used to collect information (e.g., the requirement that the police obtain a warrant signed by a judge), but not on how long the information could be retained or on the type of information that could be kept.

Some of the best‐​known limits are those set out in the 4th Amendment in the Bill of Rights to the U.S. Constitution. Although not an invention of modern libertarians, the 4th Amendment was developed by their classical liberal intellectual forebears and is of central importance to libertarian constitutional theories in the United States. It reads,

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 Warrant 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.

The 18th‐​century revolutionaries who drafted the 4th Amendment tailored it to prevent the use of the “general warrant” described earlier by requiring “probable cause” before a search and requiring the object of the search be described with particularity. But it also provides a powerful general model for controlling threats to privacy: It makes one branch of government, the executive, accountable to another, the judiciary, for proper exercise of its powers. Accountability is buttressed by the warrant requirement, which creates a “paper trail.”

In 1998, libertarian science fiction writer David Brin published an interesting work of nonfiction, The Transparent Society: Will Technology Force Us to Choose between Privacy and Freedom? In it he offered a new analysis of privacy in modern society, pointing out that high costs now follow from anonymous and concealed antisocial behavior. Because of these costs, he argued that freedom of information and openness are ultimately preferable to privacy. Governments would best be restrained by laws and technology exposing authorities’ conduct to public scrutiny. The impact of videotapings of incidents of police brutality offers an example of how this openness might work in practice. Although controversial, Brin’s work offers an important challenge to some libertarian concerns that a modern world of information technology and databases is inherently harmful. He joins those, libertarian and otherwise, who have noted that broad notions of privacy can conflict with freedom, particularly freedom of speech.

For the most part, libertarians’ concerns for privacy parallel those of civil libertarians or left liberals. There is, however, a substantial difference. Libertarians remain true to the conceptual and historical origin of privacy rights in property rights. As a corollary, they recognize the many advantages to using information about individuals and consumers voluntarily collected in the course of trade. The most familiar example is the form that credit reporting has taken in the United States. Credit reporting firms are free to collect both positive and negative information about who pays their bills. As a result, firms can make better informed lending decisions, keeping the costs of credit in the United States low compared with many other countries. Consumer data also are widely used for direct marketing in the United States, which tends to benefit consumers by forcing businesses to compete in offering more favorable terms.

By contrast, some left liberals or civil libertarians do not distinguish between the government’s use or misuse of information and the collection of information by businesses or corporations. This view is widespread in Europe, where trade in consumers’ personal information is restricted by data‐​protection laws. Somewhat ironically, although the earliest data‐​protection laws in Germany and Sweden were motivated by concerns with the growing power of the welfare state, the rules largely exempt the collection of information by government where the power to tax or pursue criminal prosecutions is concerned.

Advancing technology has affected the debate about privacy in two ways. First, modern encryption techniques allow those in the private sector to encode their messages in a manner unintelligible to the police (as they could in Thomas Jefferson’s day). Second, modern surveillance technologies give the police access to information not available through traditional searches. For decades following the end of World War II, the U.S. government sought to control and prevent the spread of encryption technology to the private sector or other countries. Notably, libertarian computer scientist Dorothy Denning shared the view that encryption was so great a threat to the state’s police powers that it should be built with hidden access for law enforcement. The majority of libertarian technologists opposed this view. Although encryption can be used by criminals, it also is useful to dissidents and vital to securing business communications. Strong encryption programs such as Phil Zimmerman’s Pretty Good Privacy became widely available around the world, while U.S. export controls on encryption software weakened the position of the U.S. software industry. The U.S. government began to abandon its controls in the 1990s. However, the debate over encryption may well revive again as Internet telephony comes into wider use.

At the same time, advances in surveillance have reduced the traditional sphere of privacy. Two centuries ago, a conversation in the middle of a plowed field would have been completely private. Today, tiny electronic bugs, satellite cameras, and other devices have changed that. Infrared cameras and other devices allow the police to see into homes through closed doors and walls. In the United States, constitutional decisions have provided some protection in the case of wiretapping (Katz v. United States, 389 U.S. 347, 1967) and infrared devices (Kyllo v. United States, 533 U.S. 27, 2001). From a libertarian perspective, these cases are not entirely satisfactory because they depend on a circular theory of privacy expectations or custom, rather than a property rights theory. It is unclear, for example, why police wiretapping without a warrant violated expectations of privacy in 1967 given that the police (and others) had been actively engaged in wiretapping since the late 19th century. Yet these cases show how difficult it is to adapt a property rights theory of privacy to modern technology as technological advances tend to blur property lines. Who, for example, owns an e‐​mail or a telephone call as it traverses wires owned by the phone company?

The terrorist attacks on the World Trade Center on September 11, 2001, brought about a new phase in the debate about privacy that is likely to have global implications. With respect to surveillance within the United States, Congress passed the USA PATRIOT Act, which reduced the role of the courts in overseeing law enforcement and intelligence surveillance. The police were given somewhat broader authority to track Internet messages and tap phones and potentially broad access to business records in intelligence investigations. Globally, the United States pressed other countries to step up their own intelligence activities, especially in tracing financial transactions.

Perhaps the most significant shift in the debate, however, was in the renewed attention given to security methods that would have a considerable impact on privacy. The government again raised the issue of national identity cards, the use of a host of biometric devices including facial recognition scanners, and, increasingly, began the development of a variety of remote sensing devices. Most significant, the magnitude of the 9/11 attacks shifted the focus of law enforcement from the after‐​crime pursuit of those who were suspected of committing crimes to preventing future attacks, the “never again” mandate. This emphasis on identifying future risks has led to proposals from the Defense Department and other quarters to compile vast databases from which patterns of normal and risky behavior would emerge statistically, as with credit reporting. Such a project would represent a fundamental shift in law enforcement methods. So far, this shift has not happened. Most libertarians would oppose such proposals.

Further Readings

Brin, David. The Transparent Society: Will Technology Force Us to Choose between Privacy and Freedom. New York: Perseus, 1999.

Denning, Dorothy. Information Warfare and Security. Upper Saddle River, NJ: Pearson Education, 1998.

Epstein, Richard. “Deconstructing Privacy: And Putting It Back Together Again.” Social Philosophy and Policy 17 no. 2 (2000): 1–24.

———. “HIPAA on Privacy: Its Unintended and Intended Consequences.” Cato Journal 22 no. 1 (2002): 13–31.

Kahn, David. The Codebreakers: The Story of Secret Writing. New York: Scribner, 1996.

Klein, Daniel B. Reputation. Ann Arbor: University of Michigan Press, 1997.

Klein, Daniel B., and Jason Richner. “In Defense of the Credit Bureau.” Cato Journal 12 no. 2 (1992): 393–412.

Singleton, Solveig. “Privacy versus the First Amendment: A Skeptical Approach.” Fordham Law Journal 11 (2000): 97.

Volokh, Eugene. “Freedom of Speech and Information Privacy: The Troubling Implications of a Right to Stop People from Speaking About You.” Stanford Law Review 52 (2000): 1049.

Solveig Singleton
Originally published