The document summarizes a keynote presentation by Ponnurangam Kumaraguru on privacy and security in online social media. Some key points: - Kumaraguru is an associate professor who researches social computing, computational social science, and security/privacy in human behavior and complex networks. - His presentation discusses research analyzing non-trustworthy content like fake news and rumors on social media. It describes building machine learning models to detect credibility of tweets about different events. - The presentation also covers challenges like privacy concerns around sharing personal details on social networks and resolving identities across different online social networks.