What Is Privacy?

What is privacy, exactly? The question has persisted for decades and continues to be posed into the digital era. Calls for precise definition in service of optimal public policy abound. Yet, like “liberty” and “freedom,” the term “privacy” defies precise definition. In the 19th century, with encroachment into family life as a principal concern, lawyers Samuel D. Warren and Louis D. Brandeis defined privacy as “being let alone.” In the 20th century, at the dawn of the computer and information ages, sociologist Alan Westin popularized “control over personal information” as a definition; and legal philosopher Ruth Gavison advanced “limited access to others” as her contribution, focusing on secrecy, solitude, and anonymity. While being let alone, controlling information, and limited access are all highly relevant to the enjoyment of privacy, it is apparent that the word “privacy” is commonly used by laypersons and lawyers to convey significantly broader meanings.