Through three case studies of online political activism on Facebook, this article conceptualizes the deployment of issue publics (Lippmann, 1993; Marres, 2005) on Facebook. We argue that issue publics on Facebook come into being through a specific set of double articulations of code and politics that link and reshape informational processes, communicational constraints and possibilities, and political practices in different and sometimes contradictory ways. Using Maurizio Lazzarato’s exploration of immaterial labour (2004), we demonstrate the need to further understand the networking of publics and their issues by considering how online platforms provide the material, communicational, and social means for a public to exist and therefore define the parameters for assembling issues and publics and circumscribe a horizon of political agency.