Sometimes Christians get upset when they see Jesus being mocked, a la Muhammed cartoons, etc. That's not the best response.
We as Christians shouldn't be surprised or offended when we hear these sorts of things though. We should be grieved for the people who say them, because they obviously don't know Jesus. Grief is a much better response than offense. It keeps us from becoming angry and defensive with other people and helps us to focus on loving them the way Jesus loved them.
Jesus was peculiar, and people hated him for suggesting that the existing power structures of his day were illegitimate, and that he would replace them with one that lifted up the dignity of all men, instead of just the priviledged few. We need to focus on lifting up the dignity of all men, too, even those who say things we disagree with.