You might also want to look at the youtube comments on any number of unblack metal bands (aka Christian black metal) such as Antestor or Sanctifica and see the sheer number of idiots that claim that black metal must be about satanism.
They're on the Amazon reviews, too. I've been working my "Not Helpful" button to the bone lately. OTOH thanks to eMusic and Amazon MP3s, I've added some really neat music to my MP3 player, from Antestor to Horde to Mortification. One nice thing about unblack metal is that if the song is preachy, I can't tell because I'm still not sure what they're singing.

OK, that can be a disadvantage as well. I don't think my sister-in-law ever believed me when I tried to tell her that CD I was listening to was Christian heavy metal. (Just because the singer sounds like he's possessed by a demon, that doesn't mean he can't be singing a Christian message.)
Edited to Add:
Dang, now you've given me another one to look for. (Tells self to search for Sanctifica later.)
I love black metal, but the scence can get pretty scary sometimes.
Yeah, I noticed.
