This article investigates how the rise of social media affects European public service broadcasting (PSB), particularly in the United Kingdom and The Netherlands. We explore the encounter of "social" and "public" on three levels: the level of institution, professional practice, and content. After investigating these three levels, we address the more general question of how public broadcasters are coping with the challenges of social media. How can public television profit from the abilities of social media to engage new young audiences (and makers) without compromising public values? And will PSB be able to extend the creation of public value outside its designated space to social media at large? While the boundaries between public and corporate online space are becoming progressively porous, the meaning of "publicness" is contested and reshaped on the various levels of European public broadcasting.