Nobody's suggesting a law against dressing like an idiot, nor is anyone saying this kid should be disciplined. This is not PC run amock. We're simply expressing outrage and offense.
I think it's important to note there's a difference between dressing as Hitler at a party in 2006 vs. if you had done so in 1942. It's obviously done for shock value, so don't be surprised if people are thoroughly shocked.
Even if it was in 2006 rather than 1942, would it be any less offensive to victims of the Holocaust, WWII vets, or their descendants? I don't think we can use distance as an excuse. If this kid shouldn't dress up as a terrorist, then no one should dress up as Stalin, Hitler, KKK, blackface, Steve Irwin, Cory Lidle, Tylenol pills or anything else.
"It's obviously done for shock value, so don't be surprised if people are thoroughly shocked."
True.