This article aims to develop a typology for evaluating different types of activism in the digital age, based on the ideal of radical democracy. Departing from this ideal, activism is approached in terms of processes of identification by establishing conflictual frontiers to outside others as either adversaries or enemies. On the basis of these discussions, we outline a typology of four kinds of activists, namely the salon activist, the contentious activist, the law-abiding activist and the Gandhian activist. The typology's first axis, between antagonism and agonism, is derived from normative discussions in radical democracy concerning developing frontiers. The second axis, about readiness to engage in civil disobedience, is derived from a review of studies of different forms of online activism. The article concludes by suggesting that the different forms of political engagement online have to be taken into account when studying how online activism can contribute to social change.