Guys at the shows and cruises are really rude

I don't go to shows much anymore. I might someday but it's not worth my time right now. Last time I did I took my girlfriend and her kids - none of whom are car people. The first time they got near a car I said rather loudly "Dont... touch... ANYTHING...". The car they were next to's owner was sitting behind the car (I didn't know he was there) and he got up and introduced himself and thanked me. Then he asked the kids if they wanted to sit in it (it was a Gasser looking Anglia - a wicked cool ride...caged, etc). Then got pictures in it, he got to talk to them about it. It was really cool of him. The next guy that said anything started raising his voice because they were getting close to his car and i simply said - "see? They're not all as cool as that last guy..."
You never know if an owner will be receptive so IMO it's always best to just stay off things. As far as telling somone to get off mine - I really didn't care when I had a car on the show field. They were just cars to me. I'd even sit on the fender when someone was talking to me...lol.