Greengrass movie -- United 93

Watched the Paul Greengrass movie last night -- United 93. It raises the important question of the representability of suffering. Actually it revisits this question, which has already been raised a lot in light of Holocaust books and films and even cartoons (Spiegelman): what can properly be represented, what is in good taste and what is tacky or in poor taste, what amounts to exploitation, etc. How do we represent such horrific and truamatic events with justice? Is the proper response just to leave an absence where there might otherwise be a (tacky, tasteless) presence? To my knowledge, no book has yet tackled this question with respect to the 9/11 commemoration industry. And trust me, it is an industry: someone's making money off all those plastic yellow ribbon decals.