This paper suggests that “systemic risk” (e.g., of financial market collapse, or of ecological calamity) has a distinctive kind of moral significance. Two intuitive data points need to be explained. The first is that the systematic imposition of risk can be wrongful or unjust in and of itself, even if harm never ensues. The second is that, even so, there may be no one in particular to blame. We can explain both ideas in terms of what I call responsibilities of “Collective Due Care.” Collective Due Care arguably precludes purely aggregative cost-benefit decision-making and requires one kind of “precautionary” attitude in public choice.