Rational Privacy Disclosure in Social Networks

Social networking web sites or social networks for short (SNs) have become an important web service with a broad range of applications. In an SN, a user publishes and shares information and services. We propose a utility function to measure the rational benefit derived by a user from her participation in an SN, in terms of information acquired vs information provided. We show that independently and selfishly maximizing this utility leads users to "free-riding", i.e. getting information about other users and offering no information about themselves. This results in SN shutdown (no functionality). We then propose protocols to achieve a correlated equilibrium between users, in which they coordinate their disclosures in view of jointly maximizing their utilities. The proposed protocol can be used to assist an SN user in making rational decisions regarding which of her attributes she reveals to other users.