Glad to here it is NOT COD4. That seemed to be about real war and real situations from the commercials I've seen.
Its technically 'Call of Duty: Modern Warfare 2'. So if you're kids got the original, don't worry, its not
as violent as this one.
I can't speak from a parents point of view, but most of my siblings video games come from me. And I let most of them play what ever they want if I know they are mature enough. There's a few that I don't let them play, mainly because of, boobie and language content, the older ones don't mind the violence of CoD, Crysis, or Fallout 3, but I do know it would bother some of the little guys because it 'realism'. Some of the more animated violent game with just a much or more blood don't bother the little ones, like Team Fortress 2. I'm glad to know that some folks out there are doing what best for their families and being active parents and learning their habits, rather than reactionary.