We propose a framework, called Derived Data Services (DDS), to ease the tension between (a) the need to mine individual's Web usage logs across multiple sites for aiding in personalization, and (b) the inherent privacy risks in it. In DDS, a standardized, hierarchical, format can be developed, whereby some higher level abstractions from a usage log can be captured, and potentially used across multiple applications. The hierarchical data structure also allows derived data to be processed incrementally based on the level of information needed, and on the level of privacy an individual wishes to have. The derived data summarizes an individual's profile in cyberspace, and should be the legal property of the individual so that access to the profile must be legally authorized by the person.