Privacy Protection for Social Networking Platforms

Social networking platforms integrate third-party con- tent into social networking sites and give third-party developers access to user data. These open interfaces enable popular site enhancements but pose serious pri- vacy risks by exposing user data to third-party devel- opers. We address the privacy risks associated with so- cial networking APIs by presenting a privacy-by-proxy design for a privacy-preserving API. Our design is mo- tivated by an analysis of the data needs and uses of Facebook applications. We studied 150 popular Face- book applications and found that nearly all applica- tions could maintain their functionality using a limited interface that only provides access to an anonymized social graph and placeholders for user data. Since the platform host can control the third party applications' output, privacy-by-proxy can be accomplished by us- ing new tags and data transformations without major changes to either the platform architecture or applica- tions.