I have written about this before in other contexts so I've thought about it a lot ... I think that humor is tricky. I do think it's okay to offend with humor. However, in the case of humor that hurts, I do think that, if people are hurt, they can say "hey, that's not funny." But the people being hurt are the ones who get to say if something is funny or not. Other people don't get to decide that for them just like other people don't get to say "lighten up, it's just a joke." So in this case, it really is Jews and Holocaust victims of which I am neither. If they say it's not funny, then that's that. At the same time, if they say "lighten up, it's just a joke" and it seems like a lot of them have, then that's that too. In the same vein, given that Joan is Jewish, this is why I get to say that she gets to tell such a joke. (Note: I didn't say it was funny. In fact, I freely admit it: I didn't get her joke.) But if tons of Holocaust victims were to protest her joke and say it wasn't funny, then I think that trumps her being Jewish. Because she's not a Holocaust victim and they are. I haven't heard of them doing that though.