Amplified by a global political climate of fear, oppression, and increased nationalism, this article examines how U.S. secondary students in a digital media elective course used multimodal composition, and video production in particular, as a nexus of 'participatory politics.' By partnering theories of multiliterate expression with youth civic engagement, it offers new understandings into how urban youth use digital media production to leverage school-based social action. Refracted through a mediated discourse analysis lens, and with a particular focus on sound as a modal resource for design, findings suggest that youth used media production and semiotic sense-making to simultaneously enliven community action as well as shield students from personal histories of trauma. By engaging in the process of digital media production, as this article suggests, students cultivated new core practices of civic interaction and local engagement by amplifying injustice.