If you don't like the artist on stage, boo him. Shit, walk out on him. But to throw stuff at him is just downright disrespectful. Sure, it's funny because he didn't represent the scenester kids there, so they felt rebellious by acting out against the mainstream, but fuckin' a. If you went to your job and got booed when you walked in the door, I'm sure you'd feel like shit. But if a fucking bottle comes flying over the wall of your cubicle, you're going to be steamed, that's for damned sure. Would it be alright for your co-workers to justify throwing shit at you because you "aren't doing anything within the genre"?
"You're not improving the quality of the Big Mac, so it's cool if I wanna be a total asshole to you and throw shit. It's justified, you know."
And The Streets fucking sucks. I don't know how anyone can seriously say that he's better than 50 Cent. I'd take 50 over that English twat any day of the week.