Adolescents are at higher risk of engaging in risky behaviors in online social networks. This project develops digital intervention solutions to motivate, educate, support and engender safe social networking behaviors among adolescents. It significantly extends the current understanding of adolescent motivations for engaging in risky online behaviors and the state-of-the-art solutions for reducing adolescent exposure to such behaviors. This project aims to educate and provide long-term improvements in online safety for adolescents, which benefits one of the most vulnerable but also educationally malleable segments of the population.In this project, the researchers investigate the connection between psychological mechanisms that render adolescents vulnerable to risky social networking behaviors and just-in-time interventions that can increase safety-enhancing behaviors. The researchers develop notifications and warnings for effectively detecting adolescents' risky behaviors. The designs of risk notifications and warnings leverage the unique combinations of social, spatial and temporal dimensions provided by social networks. In addition, the researchers leverage elements of cryptographic and other tools to devise reward mechanisms that (i) convey and reinforce safety information in an effective and ongoing basis, (ii) provide motivation for user participation, and (iii) whose correctness can be privately verified by other users. User studies are designed to evaluate the effectiveness of their proposed solutions. Instead of the standard approach of using post-hoc, self-report surveys, their evaluation approach could capture users' real risky behaviors with measures taken at the time those behaviors occur.