There is a database of every registered drone user in America. It was created by the FAA, which last year announced its requirement that all private drone owners register their craft online. The agency recently released these registration data collected since last year, which is a good chance for us in the public to analyze it. Vitally, that information lacks names and street addresses of registered owners, but since it includes city, state and zip code, it's possible to map out where drone owners are. Which is what flight restrictions mappers AirMapIO did.