I am currently stationed here in Iraq and have been here for the past 11 months; I am an adviser to the Iraqis and meet them on a daily basis. I have been in many locations in the country and am involved on a daily basis together with the Iraqis fighting the insurgency.
The media manipulation by the insurgents is brilliant and extremely effective. The press has become a puppet for the insurgents; the insurgents know exactly what they are doing with these "massacres" (quoted here because the investigation has not been completed, nor have any charges been filed) and the political nightmare they will cause the current administration. Bodies are produced for film, and there is zero fact-checking by the media--the media eat up this "news" like there is no tomorrow. A couple of hundred bucks paid by the insurgents to a few guys/ladies in the town where this "massacre" occurred to make up some bad news and pine for the BBC's or CBS's or whoever's cameras is a nice month's salary for many and money well spent by the insurgency.
All the Arabs (Sunni and Shia), Kurds and Chaldeans I have come to know well here will tell you that Arabs are emotional people who tend to exaggerate. A lot. Experience has shown that "50 insurgents hiding out in XX location" is five, at most 10. "Three hundred dead" at the morgue is at most 40. "A huge cache with WMD" is 45-50 weapons. It is a cultural norm and is accepted over here as a norm. It is reported in the West as fact. With no fact-checking.
When we convoy, all in the town/village know when and where there is a bomb/IED/VBIED that is targeting coalition forces. This is not so true in Baghdad, but in the outlying towns all know. What is the culpability for those people in the village/town? Would the Marines be guilty in the U.S. under the same circumstances?
I do not know whether or not the Marines are guilty. A Marine's job is to "close with and destroy the enemy by fire and maneuver," and I can guarantee its effectiveness. But the insurgents have the ear of the press. Hopefully the politics will be put aside for the investigation and the facts will be told, whatever they may be.