This chapter reviews the current most important theories of privacy.1 The review is
addressed to those unfamiliar with theories of privacy. It is my goal to provide those
readers with a foundation on which to build. To this end, the chapter summarizes
the two best articulated and best supported theories of privacy (Altman 1975;
Westin 1967) as well as Petronio’s (2002) communication privacy management
(CPM) theory, an important extension of Altman’s theory that is particularly suited
for the study of social networking. Additionally, this chapter considers two larger
issues about what privacy is: issues in defining privacy and lessons to be learned
from Altman’s and Westin’s theories. I begin with the three theories of privacy.