An increasing number of high-tech devices, such as driver monitoring systems and Internet usage monitoring tools, are advertised as useful or even necessary for good parenting of teens. Simultaneously, there is a growing market for mobile “personal safety” devices. As these trends merge, there will be significant implications for parent-teen relationships, affecting domains such as privacy, trust, and maturation. Not only the teen and his or her parents are affected; other important stakeholders include the teen’s friends who may be unwittingly monitored. This problem space, with less clearcut assets, risks, and affected parties, thus lies well outside of more typical computer security applications. To help understand this problem domain and what, if anything, should be built, we turn to the theory and methods of Value Sensitive Design, a systematic approach to designing for human values in technology. We first develop value scenarios that highlight potential issues, benefi...