I am separating these clips rather than embed them in what will be a God-awful (for me) long text on the subject. (Legal note: I have not confirmed the absolute accuracy of any of these so add the word "alleged" to all of the following sentences)
Pot Shooting for Kicks
Probably the most famous merc clip from Iraq, it shows British mercs from Aegis who had so much fun shooting up innocents on an Iraq road they put it to music.
The Street of the Dead
CNN's report on the most recent BlackWater attack on civilians. It is said that the Iraq government has a video of the attack that proves there was no ambush and that this was an unprovoked attack; it has not yet gone viral.
The story of this video is BlackWater mercs working for the Coalition Provisional Authority had come under attack in Najaf. Some sources claim this sniper is a Marine but, given the civilian clothing, I suspect he is a mercenary.
It's All About the Money
Iraq For Sale, a film by Robert Greenwald, take a clear look at Iraq War profiteering. This short clip explains succinctly how great the Iraq War has been for the business of BlackWater.
Treating Them Like Dogs Would Be an Improvement
This clip shows an American military contractor, possibly BlackWater, training an Iraqi police recruit.
Iraq For Sale from Robert Greenwald is the best.
Shadow Company takes a more artistic look at the profitable business of war for hire.
Private Armies from Britain's Journeyman Pictures looks at mercenaries working in Iraq and Afghanistan.