Yes, but that can’t be done preemptively, see? Anyone I meet could be anything—any religion, any race, even a neo-Nazi for all I know—and it wouldn’t be evident from their appearance. So should I just avoid all jokes that are at anyone’s expense? Isn’t it better to be unafraid about what I say and to apologize if a joke I made was at the expense of someone in the room and they were offended by it? I never intend to offend anyone, but I’ve also had quite a few good-natured laughs at others’ expense without any intention of demeaning them. I don’t see anything wrong with that if I apologize once someone is offended and then avoid making jokes at their expense around them.