Over the past decade, Kenyan citizens have actively engaged in public communication through digital media. With the growth of digital communication, questions arise about its effect on the nature and political significance of public discussion. Does the political contribution of public discussion shift if it takes place on a virtual site or in a face-to-face gathering? Looking in the context of Mombasa, Kenya, this paper provides a unique perspective about how and why there is cause for concern about the political implications of Facebook-mediated discussion. It interrogates the extent to which Facebook provides for discussion that is capable of reshaping shared imaginaries among Kenyans. To do this, I first outline the specific form that publicity takes on Facebook, taking into account both its openness and limitations. Second, I analyse what this has meant for the reconfiguration of shared political imaginaries. Drawing on the case of the public Facebook group, Mombasa Youth Senate, I argue that the conditions of Facebook create an open space that provides a great deal of flexibility in how people can appear and be recognised. However, this open and flexible experience frustrates the emergence of new and shared ideas of difference and belonging. Facebook’s underlying structures combined with user experiences are reinforcing rather than reconfiguring established ideas of citizen-state relations.