This study investigated how active mediation employed by three key socialization agents—parents, peers, and school teachers—is associated with teenagers’ engagement in online risks. A survey with 746 students aged 12–18 years found that different socialization agents focus on different aspects of the Internet when they engage in active mediation. Parents and teachers focus more on making instructive remarks whereas peers are more likely to engage in neutral facets of active mediation (e.g. helping or recommending). However, parental mediation tends to diminish whereas peer mediation tends to escalate with age among teens. The findings also suggest that school teachers’ Internet-related discussions can reduce teens’ potential exposure to online risks while peer interactions may increase teens’ vulnerability to online risks.