I live very close to the ocean and we have way too many gulls. I think of them as flying rats and can't stand them. And when I see people feeding them I come fairly close to blowing a gasket.
My wife purchased a new car about five years ago and it was two months old when gulls did their dive bomber impression and that left two permanent stains on the hood. I swear, in addition to that cat poop you mention they must eat car batteries too.
I've always thought that shooting gulls would be a great way to practice one's skeet skills. It would also reduce the inflated gull populations. Probably against any number of laws, though, not to mention what on earth do you do with the meat?
Bait crab pots?