There's a faction named ISIS and I don't think that's right. It's offensive to Christians, just like like if there was a fac related to Nazis that would be uncalled for also.
I understand why some think this is wrong however, I find it fine due to the fact you're basically saying "I think it is fine to have a fac named 1 religion, but not the other, because I don't like it."
I kinda see what your getting at but on this example I don't see it as a direct insult to one religion. They are an insult to everyone. We can kinda let the sensitivity run a mock on these type of issues. If I have a fac named Baconeaters, I could be offending Muslims. The list goes on and on......
In no way is ISIS offensive to the Christian religion. It's offensive to a tiny minority that think ISIS is directed at THEM. ISIS don't care if you're Christian... they aren't against your religion.