Digital Security For Journalists

The Judicial View of Privacy: The Fourth Amendment and Third-Party Doctrine

Over the course of many decades, the character of the American “right to privacy” has been both enshrined and circumscribed by the nature of the space in which an object or activity exists, and the process through which information about those activities is obtained. Individuals’ “persons, houses, papers and effects” constitute private realms that should not be intruded upon by the government except in the presence of probable cause and the issuance of a warrant; where a space–either virtual or physical–is shared with others, its “public” character dictates that no right to privacy exists. This dichotomy is sometimes expressed via the shorthand: “No right to privacy in public.”

Over time, the Supreme Court has occasionally interpreted and expanded the list of realms deemed “private,” and therefore safe from unwarranted search. It was in the 1967 case Katz v. United States that Justice Harlan, in a concurring opinion, coined the term “reasonable expectation of privacy” that has largely come to represent the popular understanding of a constitutional right to privacy. At issue in Katz was law enforcement’s placement of a recording device on a public telephone booth, through which it captured the contents of the defendant’s end of a phone conversation. In ruling for the defendant, the Court held that the Fourth Amendment protected “people, not places.” Harlan’s same concurring opinion asserted that “electronic, as well as physical, intrusion into a place…may constitute a violation of the Fourth Amendment.”

Yet the protections of Katz are highly circumscribed. Importantly, the contents of the conversation obtained in Katz were procured directly from the defendant himself by recording his own words. This makes Katz a “first party” to the content of the search, which is required for a Fourth Amendment claim. Because of this crucial detail, the ruling in Katz has little bearing on situations where information has been knowingly shared with others.

Though in U.S. v Warshak (2010), the Sixth Circuit asserted the defendants’ privacy interest in the contents of their emails, the law supporting the search has not proven unconstitutional.

In 1976, this distinction was reinforced in United States v. Miller, wherein the court held that there can be no expectation of privacy around information–in this case, financial–that an individual has “voluntarily conveyed and…exposed” to a third party when he or she is aware that it may be shared with still others “in the ordinary course of business.” Three years later, the court cited the Miller decision in Smith v. Maryland, which affirmed law enforcement’s right to obtain the numbers dialed by an individual when placing a telephone call, on the basis that “telephone users…typically know that the numbers they dial are transmitted to the phone company and recorded.” Under this rubric, which still applies today, telephone users have no “expectation of privacy” around the numbers they dial, even from a home telephone.

Together, the rulings in Miller and Smith help form the basis of what is broadly termed the “third-party doctrine” in American judicial proceedings, which holds that any information shared with a third party is not “private” with respect to the Fourth Amendment. As will be discussed below, only in cases where “privilege” has been established around a particular relationship (such as those with a doctor, lawyer, or, in some jurisdictions, a journalist) is there an exception to this general rule of thumb. Outside of such circumstances, Miller asserts, citizens should expect that any time they voluntarily expose information to a company or its equipment there is “the risk that the company would share that information with the police.” Though discussed in terms of privacy, it is worth noting that the decisions in Katz, Miller and Smith still hinge fundamentally on the Fourth Amendment’s protection against “unreasonable search”: Thus the core of the reasoning relates not to what was obtained, but how it was obtained. In Katz, the “search” of the defendant’s conversation was made on his own person, whereas in Miller and Smith the search was of the defendants’ financial institution and telephone service provider, respectively. The “reasonableness” of the search is therefore evaluated with respect to the rights of the organization in question, not the account holder(s), regardless of whether the search reveals information that pertains to them. Similar reasoning led to the 2012 decision in United States v. Graham , which held that “historical cell site” data–the telecommunication providers’ records of the cell towers to which a subscriber’s phone has connected–is not protected by the Fourth Amendment.