Identity Inference as a Privacy Risk in Computer-Mediated Communication

New Web 2.0 applications, with their emphasis on collaboration and communication, hold the promise of major advances in social connectivity and coordination; however, they also increase the threats to user privacy. An important, yet under-researched privacy risk results from social inferences about user identity, location, and activities. In this paper, we frame the ´social inference problem´. We then present the results from a 292 subject experiment that highlights: (1) the prevalence of social inference risks; (2) people´s difficulties in accurately predicting social inference risks; and (3) the relation between information entropy and social inference. We also show how to predict possible social inferences by modeling users´ background knowledge and calculating information entropy and discuss how social inference support systems can be deployed that protect user privacy.