Another case of US police brutality - this guy walking his dog in Denver saw a driver being stopped by police for running a stop sign. The guy thought the police had stopped the driver wrongly, and so said to the driver that he'd be happy to testify in court.
Moments later he's being kicked and punched by two burly cops who took exception to his public-spirited ways. All caught on camera. http://www.youtube.com/watch?v=_QOv9vS8Dbg