Anyone who buys into the shamelessly self-pitying whinetastic crap that is emo music. Simple. That said, since most emo kids are teenagers, they can't help being self-centered. A lot of research indicates that teenagers are, as a rule, brain damaged (literally, their rational thinking and socioemotional evaluation centers are decayed and disconnected) and thus go aound in a mask so as not to have to fess up to their confusion.
I was an emo kid for a while... now I choose not to label myself.