"I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description ["hard-core pornography"]; and perhaps I could never succeed in intelligibly doing so.
But I know it when I see it....." --- US Supreme Court justice Potter Stewart
Is the face paint offensive? Are the tattoos offensive? I guess it's up to us based on our individual opinions. And what about signs in the crowd? Are we supposed to deal with those, too?
BTW - best sign ever - UCLA/USC basketball game on TV, UCLA fan had sign that read "FLUSH USED TROJANS".