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. Presentation is part of the conference on Privacy in Social Network Sites at Delft University of Technology, October 23 and 24, 2008. www.privacyinsocialnetworksites.nl