True story-
The guy that is in the hangar directly across from my old hangar has very nice Cub Crafters Cub on floats. He told me he was moving the plane up to his place in Idaho and was thinking of getting something like a Mooney for down here. I asked him why.
Partly because of been there, done that here in California with more limited places to use a float plane, but a big part of it was he was getting sick of having the cops called on him every time he landed it somewhere. Apparently Californians don't seem to be aware that landing an airplane on water is legal and it's such a novelty here, that they freak out and call the authorities.
Once he took off from under the freeway bridge in Stockton and the FBI came calling on him! Apparently someone thought he was trying to crash his plane into the bridge. (Actually, the only violation here is a boating law. The water under this bridge is a 5mph no wake zone.) He says in Idaho, float planes are so common and people have a more live and let live attitude, so nobody freaks out about a plane on the water.
Whenever I'm out on the water with friends and somebody lands on the water, I usually get the question- "Can they do that?" I do my part to educate one boater at a time, yes, they can do that. It is legal to fly a plane on and off the water in most places.