In the United States today, only the FAA may manage air traffic across the country and that means states, companies, and cities must be inventive in managing potentially hazardous drone use. Of the current examples in use it can be broken up in to two categories, laws and repulsion.
Legally the states and cities cannot create laws to manage the drone flights, but that doesn't mean pilots are in the clear. Many laws have been passed that redefine trespassing, paparazzi, and privacy laws to include drones, penalizing the pilot for inappropriate drone usage. These laws as you may notice don’t involve regulation of the aircraft but rather expanding current local laws to encompass drone operations. The National League of Cities published a document, "Cities and Drones, What Cities Need to Know About Unmanned Aerial Vehicles (UAVs)," that clearly states these principles.
Now repulsion of drones is an extremely complex problem, as states and companies seek to invent and implement methods of detection and management within their powers and not against the FAA. The FAA has released an announcement in the Office of Airports and Safety and Standards on Oct. 26, 2016 that airports cannot test or contract with companies that want to demonstrate on or near airports. This includes detection technologies, geo-fencing, frequency jammers, and many more categories of repulsion. So as the FAA decides its position on these issues none of these methods can be guaranteed to be legal in the future.
Proper drone management is a struggle across the country, and while there are some ways laws can be applies to encourage safe drone operation, there are many gray areas that still exist.
