"Interpersonal boundary regulation" is a way to optimize social interactions when sharing and connecting through Social Networking Sites (SNSs). The theoretical foundation of much of my research comes from Altman's work on privacy management in the physical world. Altman believed that "we should attempt to design responsive environments, which permit easy alternation between a state of separateness and a state of togetherness" (1975). In contrast, Mark Zuckerberg, Facebook's CEO, claims that sharing is the new "social norm" for Facebook's 800 million users (Facebook 2011), and it is Facebook's job to enable "frictionless sharing" (Matyszczyk 2010). My research focuses on reconciling this rift between social media sharing and privacy by examining interpersonal boundary regulation within SNSs as a means to align privacy needs with social networking goals. To do this, I performed an in-depth feature-oriented domain analysis (Kang, Cohen et al. 1990) across five popular SNS interfaces and 21 SNS user interviews to understand boundary mechanisms unique to these environments and their associated challenges. From this, I created a taxonomy of different interpersonal boundaries users manage within their SNSs, identified interface features that directly supported these boundary mechanisms, and uncovered coping behaviors for when interface features were inadequate or inappropriately leveraged. By better understanding this dynamic, we can begin to build new interfaces to help support and possibly even correct some of the maladaptive social behaviors exhibited within SNSs. Finally, I conducted two empirical studies that quantitatively validated some of the relationships in my theoretical model of the interpersonal boundary regulation process within SNSs. Specifically, I examined the role of risk awareness, feature awareness, burden, and desired privacy level on SNS privacy behaviors. I also examined the relationship between privacy outcomes and SNS goals of connecting and sharing with others. Through this research, I show that boundary regulation allows SNS users to reap the benefits of social networking while simultaneously protecting their privacy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]