Reply #131: It is generally acceptable to offer criticism where due

[noamnety]

"xxx religion is stupid, its followers are insane" <-- not acceptable
"xxx religion is doing such and such which is wrong/evil/bigoted/corrupt because ... " <-- criticism of policies, good to go.

So, for example, I have harsh words about the pope's policies in this thread. At other times, I have alerted on posts which were bigoted against Christians (don't remember if those were ever about Catholics specifically, it wouldn't have made a difference to me at the time I was alerting).