"Prove it!" is a good response. I'll have to keep it in mind. Thanks.
And as for the skate-boarding kids, I can probably make them more sorry than me if the law has to get involved; they block the road and I know they've been told to clear out before. I've never bothered them when driving through (I just go very, very slowly) because I think kids should be able to play in the streets and the autos just need to go very carefully. But I've noticed that they are forgetting to show some manners; they don't really get out of the way like they used to. I'll bet I can get the police to give them more trouble than I'm likely to get for riding a motor assisted bicycle.
Maybe if the little punk yells again I'll say "I can ride, but you can't!"
That'd be kind of fun.