How can it be unlawful to shoot any civilian you want to in a war zone?

The Bush administration promised the mercenaries fighting this war that they would not have to worry about accountability, right?

Blackwater is being sued:

The Center for Constitutional Rights is filing another lawsuit today against the private military firm Blackwater—this time for a shooting in Baghdad on September 9th that left five people dead and ten injured. The lawsuit is being filed on behalf of the family members of one those killed in the shooting.

Countdown to explanations as to why this will be a blow to our freedoms... or to the glorious Eternal War on Terror and Islamofascisticevildoers... 4.. 3.. 2..