Have online social networks created one of the largest databases of identities in the world? We investigate the technical feasibility and privacy implications of combining publicly available Web 2.0 images with off-the-shelf face recognition technology, for the purpose of large-scale, automated individual re-identification. A series of experiments demonstrate a high degree of success in identifying, as well as inferring sensitive information about, strangers online and offline based on profile pictures posted on popular online social networks. The results highlight the technological and legal implications of the convergence of face recognition technologies and online social networks, and the future of privacy in an augmented reality world.