I don't know; a man was arrester in New Jersey for firing an airsoft gun in his backyard[1], since they're classified as regular firearms and require permit in that state.
Using one-off examples as it pertains to the US doesn't work very well as an argument when laws and enforcement vary so drastically from location to location.
Simply put, that isn't a good counter example to the parent's point, because it doesn't apply to more than a very small percentage of the US population.
7 million is about the population of the Randstad, the agglomeration in the west of Netherland that contains the major cities (Amsterdam, Rotterdam, The Hague, Utrecht) as well as numerous minor ones, grown together into what's practically one giant city.
But there's still 10 million people living in the rest of the country.
[1] http://6abc.com/archive/9285909/