The proliferation of small unmanned aircraft systems (microdrones) invites reconsideration of the limits of exclusive federal authority over aviation, which currently preempts state law. Public reaction to the drone phenomenon is generally adverse, putting pressure on state and local legislators to regulate drones. Many of them have enacted or are considering legislation and ordinances to do so. Many of the state and local initiatives are poorly thought out and fail to recognize that microdrones can be quite safe, relying on many internal systems that cause the drone to land immediately or to return to the launching point if something goes wrong. Most of the initiatives ignore federal preemption. In regulating drones, the challenge is how to strike the right balance between allowing lawless operation and inhibiting the deployment of a promising new aviation technology. There is room for state and local action. The number of microdrones in the air is already overwhelming the FAA’s enforcement resources. State and local law-enforcement agencies must be able to reinforce the emerging regulatory regime and to have clear ground rules for doing so. State and municipal regulation of commercial operators flying within and according to the limitations of their FAA granted authority is preempted.Organized model aircraft activity under traditional rules of the model aircraft clubs is safe. States and municipalities should focus their regulatory energies on casual hobbyists and on commercial operators who are defying FAA regulations and exemption procedures. In the long run, a cooperative federal-state regime, modeled on that used for environmental protection and occupational safety and health may be desirable.