The impact of expressiveness on the effectiveness of privacy mechanisms for location-sharing

A recent trend in social networking, photo/video sharing, and location-sharing services is a demand for more expressive privacy mechanisms that provide greater control over the conditions under which information is shared. We provide a methodology to inform the design of such mechanisms by identifying the most relevant privacy dimensions for a particular user population. We performed a week-long user study where we tracked the locations of 30 subjects. Each day we collected their stated ground truth privacy preferences regarding sharing their locations with different groups of people. Our results confirm that i) most subjects had relatively complex privacy preferences, and ii) that privacy mechanisms with higher levels of expressiveness are significantly more efficient in this domain. Keywords Expressiveness, Usable privacy, Location sharing, Web services, Social networking, Mechanism design

• Type: Conference
• Year: 2009
• Where: SOUPS
• Authors: Michael Benisch, Patrick Gage Kelley, Norman M. Sadeh, Tuomas Sandholm, Janice Y. Tsai, Lorrie Faith Cranor, Paul Hankes Drielsma
• Keywords: Privacy, Privacy Mechanisms, Privacy Preferences, Security Privacy, SOUPS 2009