Title: When being Weak is Brave: Privacy in Recommender Systems

Abstract: We explore the conflict between personalization and privacy that arises from the existence of weak ties. A weak tie is an unexpected connection that provides serendipitous recommendations. However, information about weak ties could be used in conjunction with other sources of data to uncover identities and reveal other personal information. In this article, we use a graph-theoretic model to study the benefit and risk from weak ties.