Trust-Enabled Privacy: Social Media Designs to Support Adolescent User Boundary Regulation

Abstract: Adolescents heavily rely on social media to build and maintain close relationships, yet current platform designs often make self-disclosure feel risky or uncomfortable. Through a three-part study involving 19 teens aged 13-18, we identify key barriers to meaningful self-disclosure on social media. Our findings reveal that while these adolescents seek casual, frequent sharing to strengthen relationships, existing platform norms often discourage such interactions. Based on our co-design interview findings, we propose platform design ideas to foster a more dynamic and nuanced privacy experience for teen social media users. We then introduce \textbf{\textit{trust-enabled privacy}} as a framework that recognizes trust -- whether building or eroding -- as central to boundary regulation, and foregrounds the role of platform design in shaping the very norms and interaction patterns that influence how trust unfolds. When trust is supported, boundary regulation becomes more adaptive and empowering; when it erodes, users resort to self-censorship or disengagement. This work provides empirical insights and actionable guidelines for designing social media spaces where teens feel empowered to engage in meaningful relationship-building processes.