Drawing on themes important in moral and political philosophy, much of the scholarship on the constitutional law of privacy in the United States distinguishes between privacy understood as a person's control over information and privacy understood as a person's ability to make autonomous decisions. For example, Katz v. United States (1967) established the framework for analyzing whether police activity constituted a “search” subject to the Fourth Amendment's requirement that the police either obtain a warrant before conducting a search or otherwise act reasonably. The defendant was a professional gambler who knew enough about police techniques to use a public telephone to make his business calls. Police agents attached a listening device to the outside of the phone booth, and sought to use the recordings against the defendant. The Supreme Court agreed with the defendant that the Fourth Amendment had been violated. Justice John Marshall Harlan's influential concurring opinion asserted that a person's privacy, in the sense of control over information, depended on two factors: “that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as ‘reasonable.’” Fourth Amendment cases like Katz involve informational control; they define the circumstances under which the government may acquire information from or about a person without first obtaining the person's agreement. In contrast, cases like Griswold v. Connecticut (1965), which barred the state from making it a criminal offense to use contraceptives, and Roe v. Wade (1973), which restricted the state's power to prohibit or regulate abortions, used the language of privacy rights to protect a much broader interest in autonomous decision-making. Seeing these cases and related ones through lenseees provided by moral and political philosophy, scholars have attempted to describe what a morally sound constitutional law of privacy would be, and the broadest sense, dworkinian. That is, they seek to provide an account of privacy with two characteristics: it is broadly consistent with the relevant constitutional decisions, and it is the most morally attractive account possible that satisfies the requirement of consistency with the decisions.
