Firstly, yes i am and i've never met anyone who isn't but

I was arguing with a friend of mine tonight about an album he put on. The album was called "Harvesting the c___ nectar" by XXX Maniak (edited slightly by me but its obvious) and i felt that the album went beyond what was acceptable, the music was excellent but the lyrics centred around necrophilia, paedophilia and sexual violence. I was saying it was offensive and unneccessary. The point he was making was that it was liitle different to bands like Slayer, Cannibal corpse and Deicide who i will happily listen to, only pushing taboos a bit further. So my question is, when does music become unacceptable? And how much responsibility do artists have for the reactions of listeners? (i.e. should bands refrain from discussing these topics in case people think "Oh its cool and so and so sing about it so it's not just me")