Information technology plays a pivotal role in New Labour’s modernization programme. Here we report findings from a 2 year ethnographic study of the impact and origin of one such system, the Integrated Children’s System, which has been deployed in statutory children’s social care. We show how the ICS, by attempting to micro-manage work through a rigid performance management regime, and a centrally prescribed practice model, has disrupted the professional task, engendering a range of unsafe practices and provoking a gathering storm of user resistance. We attribute these paradoxical outcomes to inherent flaws in the design of ICS, which derive from the history of its development and its embodiment of an audit-driven, inspectorial ideology. We conclude with some suggestions for user-centred design and policymaking, which have relevance not only for children’s social care but for the public services in general.