Unless it is a group you belong to. Then its comedy. Since moving to the US I have watched with bemusement as long stand up routines by black comedians explain that black people have no money, commit crime and beat their children (it's funny 'cause it true ?! WTF?). Thus, it is also okay if you can get any single person in the maligned group to agree that what you are saying is a joke, not a slur.
It's okay if you hate everyone so long as you are thorough. Apparently being a complete bastard is the same as being nice. In fact that's just being "honest". So long as honesty consists of thinking pretty much anyone on the planet is a congenital moron other than ones self. (Is the idea that because everyone is something, total hate somehow cancels out into total love like subtracting negative 1?)
Its okay if the group you disdain is privileged. If you are famous you signed a pact with the public, and your life is now our circus. If you are beautiful, you are a spectacle and anything you do that is less than perfect is a sign of you basic lack of moral worth. Its okay to hate people who have things we don't because that is how everyone ends up equal, which is the whole point of being anti-prejudice right?
You can be beautiful so long as you don't mind be mocked--it is society's handicapping system.
It's okay, really.
It's more than okay, it's funny!
They deserve it.
Are you in on the joke?