O.K.
1. Beiber: No.
I don't get why everyone picks on him specifically though. I mean, sure, he's a bit of a smeghead and his music is beyond horrible but surely there are others out there just as bad? Anyway, I can't stand him and he sure isn't metal.
2. Slipknot. Yes.
They are aggressive, solo-playing, heavy-riffers. Probably not the world's best metal, though, I'll admit.
3. Korn. Yes.
I only like a few of their songs but I'd still call 'em metal.
4. P.O.D. Never heard of them, no idea !
5. Avenged Sevenfold. No.
I used to think that they were but in all honest, bar an arguable couple of songs, they are rock.
6. Linkin Park. Used to be.
In the glory days I would say absolutely. However, they are now definately rock.
7. System of a Down. Don't know anything about them.
8. Godsmack. Yes.
How can Godsmack not be considered metal!
9. Disturbed. Yes.
One of my favourite bands, though as I remember they themselves don't really care about the title and tend to think of themselves more in terms of Hard Rock. I call 'em metal!
10. Rob Zombie. Dunno him!
11. Rammstein. Yes.
I haven't heard a lot but I know it's metal.