Knowledge is not static or unique. It can be exchanged between activists, academia and policy circles: from science to activism and from activism to science. Existing scientific knowledge is being used by activists to expose wrongdoings or improve practices and knowledge in environmental and health conflicts. Activists can either adopt scientific knowledge and data in their own argumentations or produce new scientific knowledge either by becoming scientists themselves or in co-operation with experts. Local and scientific knowledge is being combined to challenge government policies and the knowledge produced by corporate actors. Also explored is the figure of the expert-activist; with scientists becoming activists and vice versa, the boundaries between activists and scientists are increasingly blurry.