One increasingly important development for which firms need to find innovative solutions is the growing attention to corporate social responsibility (CSR). The shaping of CSR can be seen as a process in which firms and a variety of other actors are involved. This paper highlights the role of activists, and especially the role of networks of activism, in the process of (re-)defining, and sometimes innovating, the role of firms in issues of CSR. This can be seen as a process of institutional change in which norms are changed. Therefore, this paper contains a short theoretical examination of three relevant literatures (social movements, institutional theory and social network analysis) to flesh out some of their commonalities in order to develop proposals for a further research agenda for understanding how networks of activist groups (and firms) operate in shaping corporate social responsibility - an issue highly relevant in understanding the changing role of business in society. In addition, such insights can also contribute to understanding the role of activists in influencing innovation trajectories. © 2012 Blackwell Publishing Ltd.