Privacy interfaces for information management

To facilitate the sharing of information using mode rn communication networks, users must be able to decide o n a privacy policy—what information to conceal, what to reveal, and to whom. We describe the evolution of pr ivacy interfaces—the user interfaces for specifying privac y policies—in COLLABCLIO, a system for sharing web browsing histories. Our experience has shown us that privac y policies ought to be treated as first-class objects: po licy bjects should have an intensional representation, and priv acy interfaces should support direct manipulation of thes e objects. We also show how these conclusions apply to a varie ty of domains such as file systems, email, and telephony.