This article contextualizes Indymedia, the Internet-based network of Independent Media Centres (IMCs) that has developed since the 30 November protests in Seattle against the World Trade Organization talks there in 1999. In a short space of time this network has become the backbone of communication for the broad coalition of groups that comprise the anti-capitalism movement. Context is sought from three perspectives: first, through a consideration of new social movement use of the Internet as a radical, socio-technical paradigm to challenge the dominant, neoliberal and technologically determinist model of information and communication technologies (ICTs). Second, the article regards Indymedia as the most current manifestation of radical Internet use. It examines the (inevitably) brief history of such use, exploring examples of praxis by anarchist groups, the Zapatistas and factions of the anti-capitalism movement, and assesses Indymedia’s place in this history. Finally, the nature and value of Indymedia are assessed using the theoretical tools afforded by recent alternative media scholarship: in particular, Indymedia is examined in terms of its organization, its socio-politics and its news cultures.