OK, but Islam per se is not the problem; the problem is religion. When an atheist trashes Islam, every Christian within earshot thinks, “Goddamn right Islam sucks,” which means every Christian within earshot misses the point.
By all means, trash Islam; it’s a stupid religion. But they all are. And if you’re going to trash Islam, make sure you do it from a position of strength. And for fuck’s sake don’t let the Christians think you’re on their side.