Some 45 state legislatures considered regulation of drones this year, according to the Administration. Chicago became the first large US city to regulate drones when it introduced its own rules and restrictions in November. 

Coded warning

The office of the chief counsel of the Administration has now asked state and other local regulators to consult with it before setting up their own rulebooks, which is being seen as a coded way of warning them off. The Administration said: 'Substantial air safety issues are raised when state or local governments attempt to regulate the operation or flight of aircraft.' Source: Slate