Discursively constructed norms about “good” parenting have long tasked parents with monitoring their children’s activities to ensure their safety. Yet contemporary digital media complicate the task of the good parent who is expected to not only know where their children are and what they’re doing, but also what they’re doing online and with digital media. This article draws on qualitative research with forty Australian parents of teenagers to determine the various ways that parents monitored and acquired knowledge about their children’s online activities. Five primary techniques were identified: 1) physical observation; 2) digital surveillance; 3) trust-based and discursive strategies; 4) restriction and control through social or technical means, and 5) talking with other parents. This article contributes to parental mediation literature by exploring what parents know about their children’s online activities, and how they acquire those knowledges. This article points to a number of challenges experienced by parents in monitoring and mediating their children’s online activities, and argues that parents are defaulting to trust-based and discursive strategies as other forms of mediation fail.