To Self-Persuade or be Persuaded: Examining Interventions for Users' Privacy Setting Selection

User adoption of security and privacy (S&P) best practices remains low, despite sustained efforts by researchers and practitioners. Social influence is a proven method for guiding user S&P behavior, though most work has focused on studying peer influence, which is only possible with a known social graph. In a study of 104 Facebook users, we instead demonstrate that crowdsourced S&P suggestions are significantly influential. We also tested how reflective writing affected participants' S&P decisions, with and without suggestions. With reflective writing, participants were less likely to accept suggestions -both social and Facebook default suggestions. Of particular note, when reflective writing participants were shown the Facebook default suggestion, they not only rejected it but also (unknowingly) configured their settings in accordance with expert recommendations. Our work suggests that both non-personal social influence and reflective writing can positively influence users' S&P decisions, but have negative interactions.

• Security and privacy → social aspects of security and privacy.