Privacy is a difficult concept when designing appropriate measures to prevent threats to privacy from materializing. Professor Jeroen van den Hoven of Delft University of Technology presents a conceptualization of privacy that aligns with data protection. He tests this conceptualization on Social Network Sites. Q&A session after the presentation, which is part of the conference on Privacy in Social Network Sites at Delft University of Technology, October 23 and 24, 2008. www.privacyinsocialnetworksites.nl