Most posts about this movie...
...seem to have been made by fairly articulate people who are getting carried away by emotions caused by a shocking final scene. The majority of the people slating the movie are in fact basing their criticisms on their own MISinterpretations. As an example, the constant remarks about lack of realism and the fact that 3 or 4 exposures of to class A's will turn teenagers into murderers and rapists. I can say with near certainty that this was not what was being implied in the movie.
I think this was a good movie with a number of excellently executed segments. There were more scenes that were memorable for their cinematography and direction than I have seen in the past 30 movies I've watched. These may have been drawn from the work of classic directors such as Kubrick but who doesn't draw inspiration from elsewhere. Even the recent "There Will Be Blood" had a certain deceased director to thank for much of its greatness. And lets not forget we had a 25 year old writer and director at the helm here.
And before the legion of incensed myopics start attacking me, let me just say that I was indeed affected by the final scenes. It stuck in the forefront of my mind for at least a few days. It was horrible but I see 'horrible' scenes all the time and have forgotten them before the credits roll. There is a broken bottle gang rape in the movie WAZ (W-delta-Z). The Saw and Hostel movies contain innumerable scenes of torture. Practically every teen horror has scenes of innocents being subjected to the unspeakable. The final scene in this movie sticks with us longer and affects us more because of HOW it was shot. Just like the rape in A Clockwork Orange, the suicide in Full Metal Jacket or the orgy in Eyes Wide Shut. It sticks because of quality of direction and cinematography and for me at least, the fact that I felt nauseated by it is a sign of its strength rather than a reason to attack it.
Avoid this movie if you are of a weak or nervous disposition. Otherwise watch it and analyse each scene rather than judging ninety minutes on the basis of your body's reaction to the final four.