For more than thirty years an extensive and significant philosophical debate about the notion of privacy has been going on. Therefore it seems puzzling that most current authors on information technology and privacy assume that all individuals intuitively know why privacy is important. This assumption allows privacy to be seen as a liberal “nice to have” value: something that can easily be discarded in the face of other really important matters like national security, the doing of justice and the effective administration of the state and the corporation. In this paper I want to argue that there is something fundamental in the notion of privacy and that due to the profoundness of the notion it merits extraordinary measures of protection and overt support. I will also argue that the notion of transparency (as advocated by Wasserstrom) is a useless concept without privacy and that accountability and transparency can only be meaningful if encapsulated in the context of privacy. From philosophical and legal literature I will discuss and argue the value of privacy as the essential context and foundation of human autonomy in social relationships. In the conclusion of the paper I will discuss implications of this notion of privacy for the information society in general, and for the discipline of information systems in particular.