Extant literature in information systems often reports a significant level of unease among the Internet community with regard to threats to online privacy but fails to identify a comprehensive set of specific online privacy concerns. Moreover, out of the concerns that have been identified by a number of surveys, it is unclear whether any have adequate theoretical foundations. This paper uses the existing privacy literature and in particular the work of two prominent privacy theorists, Westin and Altman, to devise an online privacy model which outlines the components of the online privacy concept and their interdependencies. A theory for online privacy is then derived from this model.