This talk develops the proposal that a central – and neglected – ethical challenge for the field of AI is demystification of the techniques and technologies that constitute it. Demystification goes beyond questions of fairness, accuracy and transparency (although those are certainly relevant), to the problem of how we might set out clearly the prerequisites for the efficacy of AI’s operations. To make more concrete what she means by demystification, Lucy will examine the case of so-called ‘pattern of life’ analysis in the designation of persons and activities identified as posing a threat to the security of the US homeland. ‘Human-centered AI’ takes on a darker meaning in this context, as the human becomes centered in the cross hairs of a system of targeting, whether for assassination or incarceration. Lucy will close with some suggestions for how we might proceed with the project of demystification, beginning with an articulation of the limiting conditions as well as the unprecedented powers of contemporary algorithmic systems.