Is it sick to enjoy art which discusses or even encourages sick things?

Is it sick to create art which discusses or even encourages sick things in a way attractive to "normal" people?

Or is it just brilliant to get people to think about uncomfortable things by messing with their heads a little - by making something beautiful from ugliness?

Can discussing anything ever be bad? Doing bad things is bad, but thinking about them, talking about them... whether that's good or bad probably depends on why you are doing it and what your goals are. But if the artist can't control how people are moved by his work - is he playing with fire? Is it justifiable? The religious right usually claims it isn't. But since I'm enjoying art (music) which has these traits, I wonder how to defend it's creation rationally against such arguments - I enjoy it, it makes me feel better, it doesn't make me do bad things. But I wouldn't want to have to explain some of the lyrics to a six-year-old...

Tool