Art at the World Trade Center site on September 11th may be offensive to some people. But I'd venture a guess that those people don't know shit.
September 11th is an incredibly important date in the world's history. It was the advent of pervasive American fear and pervasive fear in the rest of the world: were they going to be attacked? And if they were in the middle east: would the US attack them?
Question authority; make people uncomfortable and mad at you. That's what art is about. That's what dissent is for. And that's what wars like Iraq inspire. Oh, did I mention that
Question. Act. Art.