An extraordinary large-scale student movement in Hong Kong successfully forced the government to withdraw a patriotic education proposal in 2012. The student group has attracted serious scrutiny from the pro-government camp because of the students' unusually young age and remarkable mobilising power. This study aims to explore the community structures and identify significant members in the student network, and to shed light on understanding of the formation of young activists' sense of civic identity in the Internet age. Techniques of social network analysis were employed. It is argued that the role of adult activists and the role of social media are inadequately researched in civic education studies. Moreover, it is further argued that the post-colonial city presents a kind of phobia of talking about the adult–student relationship in civic action, which may risk hindering rigorous discussion of youth civic engagement.