This introductory chapter surveys the meanings of privacy in three domains—the first, involving intimacy and intimate relations; the second, implicating criminal procedure, in particular the Fourth Amendment; and the third, addressing control of information in the digital age. The first two provide examples of what are taken to be classic breaches of the public/private distinction—namely, instances in which government intrudes in an area claimed to be private. The third has to do with voluntary circulation of information and the question of who gets to control what happens to and with that information. An overview of the subsequent chapters is also presented.