What Mortimus above me said ^^
Ask always for permission and don't sneak-hug-attack them.
The suit I have now (a wolf suit) was actually worn by its maker to a con and someone thought it was an amazing to surprise-hug her from behind and the jaw broke
The person ran away straight after and until this day no one has found out who he (or she) was.
She fixed it up very well, but it's still a situation that wasn't nice for her as she didn't know if -at the time- she could fix it. Also, it costs sometimes a lot to fix things if they are in fact fixable. (Wasn't nice for me either, since I wanted to buy it over from her ._.)
As also having worked at a convention, I can say that in most cases it is not appreciated to run indoors. Be respectful and patient towards others. This means other con-goers, security, staff, volunteers, and artists.
I think most have already said all that I wanted to say as well, so I hope you have fun ^^