I have to say, after watching that video, I'm not sure what all the fuss is about.
Those vehicles have big signs on them telling the locals to stay away, or they will be fired upon. To me, it's not a difficult concept, especially in the land of suicide bombers, kidnappings and VIEDs.
Consider what would happen if you took a run at local police forces' checkpoint during the holiday season, and sped towards them, when there were signs to the contrary. You would be shot - and rightfully so. The fact that these PMC's lived to tell the tale means that they were doing something right - it just was'nt putting the film on the web.