Although extensive research has examined social media nudges to influence privacy, comparably less work investigates mechanisms of peer-to-peer influence, or the ways in which peer groups can amplify or dampen privacy considerations. This study takes an experimental approach to examining how people are influenced to share potentially sensitive photos of others without consent---a common practice on social media---by comparing the effects of encouraging, discouraging, or mixed feedback social media comments. The results show that discouraging peer comments reduce the sharing of others' photos when content portrayed targets negatively. However, peer influence backfired among users with a history of online misconduct, with both encouraging and discouraging comments leading to more photo sharing. Moreover, a mix of comments that both discouraged and encouraged sharing led to the highest levels of sharing. Linking to prior work, this research establishes a broader understanding of when privacy nudges are likely to backfire on social media: for users with past online misconduct and when information goes against social norms. The findings advance understanding of how peer-to-peer dynamics shape online information flows and highlight the complex effects of Web-based social feedback on privacy decisions. These insights provide actionable design recommendations for platforms to foster responsible, privacy-conscious sharing norms.

Although a great deal of research has examined interventions to help users protect their own information online, less work has examined methods for reducing interdependent privacy (IDP) violations on social media (i.e., sharing of other people's information). This study tested the effectiveness of concept-based (i.e., general information), fact-based (i.e., statistics), and narrative-based (i.e., stories) educational videos in altering IDP-relevant attitudes and multimedia sharing behaviors. Our study revealed concept and fact videos reduced sharing of social media content that portrayed people negatively. The narrative intervention backfired and increased sharing among participants who did not believe IDP violations to be especially serious; however, the narrative intervention decreased sharing for participants who rated IDP violations as more serious. Notably, our study found participants preferred narrative-based interventions with real world examples, despite other strategies more effectively reducing sharing. Implications for narrative transportation theory and advancing bottom-up (i.e., user-centered) psychosocial interventions are discussed.