Like the famous quote from a judge,"I'll know it when I see it", regarding the legal definition of what is or isn't obscenity, things like this are on a sliding scale based on the individual (or culture) so I'm not sure there really is an answer.
There is a part of me that totally agrees with sensitivity to others, and there is another part of me that knows that is a slippery slope and things can start to get overly repressive to protect the more delicate sensitivities of the few, some of whom seem to have made a career out of being scandalized about one thing or another that to most simply bring a smile to their faces. Since the few are usually the most vocal, sometimes for self-serving reasons IMO, I usually try to error on the permissive side just to be a counterweight to the professional scolds.
I agree with Mr. Van that the U.S. has some screwed up obsessions over some pretty silly stuff, but also think of other cultures that seem to be even more screwed up that we are so I guess it could be worse
