This article examines how European activists engage with law both strategically and under coercion. It argues that the expanding shift of social conflict into judicial arenas has produced a continuum of activist–law interaction, ranging from strategic NGOs’ litigation to activists’ experiences of criminal prosecution. To capture these forms of interaction and law’s dual role in enabling and constraining collective action, the article develops the concept of “contested justice,” a framework that integrates socio-legal research on legal mobilization with social movement scholarship on legal repression. Drawing on protest-related criminal trials in Germany and environmental litigation in Spain, the article shows how activists operate within and against judicial processes that simultaneously enable mobilization and impose constraints. By situating civil and criminal cases within a shared conceptual field of law in contention, the analysis advances theoretical dialogue across socio-legal studies, political sociology, and social movement perspectives.