The penetration rate continues to grow for social networking sites where individuals join a virtual community to socialize, make connections, and share opinions with those who have similar interests, while revealing personal information. However, online social networking presents a unique context with distinct privacy challenges. To understand information disclosure behavior in this context, we apply the extended privacy calculus model, developed by Dinev and Hart (2006a), which addresses the trade-off between the expected costs of privacy risk beliefs and the benefits of confidence and placement beliefs on the willingness to provide personal information. We further extend this model to include specific types of personal information, based on our proposed taxonomy of information integral to social networking. To test our research model, a questionnaire will be administered to undergraduate students, drawn from the mid-Atlantic U.S. For hypothesis testing, structural equations modeling will be used. The completion of this research-in-progress study is expected to contribute to our understanding of the types of information revealed in online social networking.