Public coverage of the potential of new technologies is dramatically increasing, from expanding capabilities offered by the net and mobile phones to robotics. The introduction of these new technologies is commonly measured in relation to cutting the administrative burden, software costs, vendor independence and the deployment of human resources. The ethical implications of rolling-out such applications are rarely debated for either able-bodied citizens or for those less able to reach informed decisions and exercise individual consent. This chapter examines the challenges for those required to demonstrate public accountability for the use they make of identity verification techniques for public policy purposes, ranging from border controls to accessing public services. It concludes that accountability mechanisms are not yet sufficient to the task of retaining public trust in either the technologies or in those deploying them in the name of security.