David Garcia: Online privacy as a complex phenomenon

Preserving individual control over private information is one of the rising concerns in our digital society. Online social networks exist in application ecosystems that allow them to access data from other services, for example gathering contact lists through mobile phone applications. Such data access might allow social networking sites to create shadow profiles with information about non-users that has been inferred from information shared by the users of the social network. I will present our work on testing this privacy risk for sexual orientation, marital status, and location inference in Twitter and Friendster, a disappeared social network. Our findings illustrate that individuals are not in full control of their online privacy and that sharing personal data with a social networking site is a complex decision that is collectively mediated by the decisions of others.