This article analyses how early twenty-first century political activists in Italy construct the frontier between politics and violence. It puts these constructions into the context of more conventionally theoretical accounts of violence and politics. Analysis of internet discourse published by left/anarchist bloggers and group members focusses on how activists criticize the conventional view that electoral politics is non-violent, and endorse the view that violence is politics’ main means. This means that the role of violence in oppositional politics then has to be negotiated. Discourse analysis shows how ideas of resistance, and anti-state force, are articulated in such a way as to draw distinctions between us and them, and their politics and ours. The article discusses the significance of these articulations of the politics-violence distinction for the construction of political agency, and for the justification of forms of political action, seeking to show that boundary work is fundamental to political agency.