This paper looks at the deployment of a medical technique, reflex anal dilatation and contrasts the way in which its deployment was a subject of enormous controversy in the Cleveland child sexual abuse affair with its comparatively unproblematic previous use to identify homosexuality. We interpret this contrast using two general frameworks: recent work in the sociology of scientific knowledge, particularly actor-network theory, and Foucauldian work on dangerousness and visibility. We argue that the specific historical conditions surrounding the two different deployments allow an understanding of why the deployment of the technique was resisted in one case but not in the other. While Foucault helps us to understand the potential for contestation between the proponents of RAD in Cleveland and actors such as families and politicians, actor-network theory enables us to examine how such conflict actually arose through tracing the sorts of resources that could be mobilised in problematising RAD. In particular, we note that the antagonists of RAD had available a 'practice of rights' towards which they could orient themselves in their contestation of the 'practice of care' that informed the activities of the RAD proponents.