Social networking sites have been rapidly adopted by children and, especially, teenagers and young people worldwide, enabling new opportunities for the presentation of the self, learning, construction of a wide circle of relationships, and the management of privacy and intimacy. On the other hand, there are also concerns that social networking increases the likelihood of new risks to the self, these centring on loss of privacy, bullying, harmful contacts and more. This article reviews recent findings regarding children and teenagers' social networking practices in order to identify implications for future research and public policy. These focus on the interdependencies between opportunities and risks, the need for digital or media literacy education, the importance of building safety considerations into the design and management of social networking sites, the imperative for greater attention to "at risk" children in particular, and the importance of a children's rights framework in developing evidence-based policy in this area.