The rise of social media has coincided with the emergence of an expressive citizenship model that emphasizes the role of expression in networked environments centering on personal interests. Yet relatively little is known about how civic participation might develop from daily, general social media use. Drawing on communication infrastructure theory, this study uses two-wave survey data from Taiwan to investigate which types of Facebook users are more likely to become civic action takers and how. Results show that high public expressers—those who manifest higher levels of public expression (e.g., updating status)—have more integrated connectedness to the civic information sharing network, which in turn facilitates civic participation. This pathway to civic participation is relatively open to users with diverse levels of political interest. Overall, these findings help to explain how general social media users become civic action takers, presenting important implications for addressing inequalities in civic participation.