Stereotype victims that can be categorized as a subgroup along with jocks, plastics, etc. Often seen as a genre of depressing or terrible music, and kids who feel sorry for themselves or dress in certain way; kids that develop eating disorders, cut themselves, and overdo the sensitive thing. They supposedly look down on the rest of the world and have completely irrational or absurd reasons to be this way. In truth, they might be this way, they might not. It may be for good reasons, and these definitions are only making things worse.
Not all emo people cut themselves, wear tight pants. or are all depressed. Ever heard of emo-happy?