The Blackwater Security Company is one of many companies in Iraq providing security to State Department and other officials and contractors. The New York Times reported that there were 7,000 security men operating in Iraq. A Blackwater detail was involved in a firefight recently and the Iraqi government claimed that a lot of innocent civilians were killed. The Iraqis government's immediate reaction was to order Blackwater out of the country.
I had my own experience withe Blackwater when I was in Karbala. I wrote an account of this visit in my book, and I have included that account with some pictures here on my site.
This was in 2004, but I still noticed that the Blackwater people didn't have a lot of patience with the Iraqi drivers. If an Iraqi was in the way, the would bump his vehicle in the rear, causing him to move over and let the convoy by. These Blackwater guys had a tough job in a rough environment, but if I was an Iraqi I would have a problem with the way the average citizen was being treated. I imagine that the reaction of the Iraqi government is a kind of payback for the sum total of indignities that the Iraqis have suffered the last four years from Blackwater and other security companies.