Why exactly do tourists pose for smiley tourist-photos in front of the construction site that is Ground Zero? This is not an occasional occurrence, but enough of a thing that walking to campus from Battery Park City requires dodging a horde of those doing so. I don't hold it against tourists that they, you know, tour, nor do I see anything wrong with shopping for discount designer goods at Century 21, on account of its unfortunate location just across the street from where it happened (and I take it shopping, not 9/11-commemoration, is the draw for some, particularly the Europeans). I do ask, of those ostensibly there to visit Ground Zero, who (if their interest in flag-adorned items is any indication) are visiting as patriots and not as al-Qaeda-sympathizers, why so cheery, given the location and the reason for its significance? Do tourists also pose grinning in front of former concentration-camp sites in Europe? Is this a sort of 'I was there' impulse that can't be turned off, along with a compulsion to smile in pictures? Any ideas?