Improving personal privacy in social systems with people-tagging

The recent emergence of social systems has transformed the Web from an information pool to a platform for communication and social interaction. As such, the issue of managing privacy of various types of user-created content in these open environments has become more of a concern. Existing social systems often define privacy either as a private/public dichotomy or in terms of a "network of friends relationship, in which all friends" are created equal and all relationships are reciprocal. We explore instead the idea of tagging people to create ego-centric groups of dynamic, non-reciprocal relationships to improve privacy management in this domain. In this paper, we introduce the principles and motivations behind people-tagging, discuss constraints that make people-tagging safe, trustable, and spam-free, describe a research implementation we have created to experiment with the concept, and provide the results of a preliminary empirical evaluation which shows the strength of the idea and indicates areas for future enhancements.