If you look very very closely at the trailer, at 1:33, during the split second scene in which Adrian Veidt first swings a stanchion at a bad guy, you will notice that the bad guy is holding a large walkie-talkie in his hand rather than pointing a gun. This was done because the MPAA would not allow a scene depicting a gun being pointed at the camera in a regular green band trailer. The next scene shows the same bad guy holding a gun, but pointed away from the camera.
