I posted this on the comment line, but I think I should make it a post as well.
As I understand it, some atheists have been using the admittedly bloody history of Christianity as grounds for atheism, claiming that atheism is pure in that regard. I find this patently absurd. You get the blood when the power of the state is attached to any ideology, whether it be a Christian ideology, a Jewish ideology, a Hindu ideology or an Islamic ideology, or an atheist ideology. Can people be fanatical enough about atheism to kill for it? I realize that they don't believe in hell, but some of them are exclusivists in the sense that they think everyone who is on the atheist side is right and everyone who is committed to "religion" is doing damage. When someone can't recogize the fact that Gandhi received profound inspiration from his Hindu beliefs while challenging the worst in Hinduism, if you call Martin Luther King insane because he was caught up in the "God delusion" and can't see how important his faith was in undergirding the social transformation he spearheaded, then you are an ideologue, and I'm going to start getting worried if you ever have a gun in your hand.
State-sponsored Christianity, state-sponsored Islam, state-sponsored atheism. Is the problem with the beliefs, or with the misguided attempt to support these ideologies with coercive power. The bad news for atheists is that the bloody history of Christianity does nothing to support a case against Christianity. The good news for atheists is that these things do support something that I think most atheists believe in: the separation of Church and State. That is the correct use of the"holy horrors" argument, and atheists who want to use it in that way can be my guest.