Widespread adoption of interactive, peer-to-peer digital media will require a solution to the Privacy, Sharing, and Interest (PSI) problem: how can we know what the user wants to share with whom, and when, without burdening the user with constant updating of lists of approved users and sharing preferences? We argue that real-time analysis of user behavior provides an automatic PSI capability, allowing media to be automatically and proactively shared with a much lower user burden.