I hear ya, I would be pissed the fuck off if anyone spat on me or dumped/threw anything at me. It really does amaze me how fuckin stupid and disrespectful some people are. If someone's being a total asshole, then by all means do what you gotta do.
I don't get why people have to fuck with those that are at a game minding their business. By that, I don't mean heckling someone and talking shit in good fun...I'm talking about flipping them off, throwing shit, that type of disrespectful behavior.