re: "Imagine that, he survived WAR in Iraq & is in critical condition in the good old USA."
clo,
Of course, we have to keep an open mind.
We don't know the circumstances. It's not as if the "grenade" caused harm. It emitted gas and dispensed the crowd.
Consider: There's an injured guy on the ground. The police and medics can't even get to him to help because of the unruly crowd. Did they have a better option? The more I think about it, the more I think maybe not. While the video at first seems to be a case of shocking police brutality, that may just be how it has been SPUN.

Gold is $1,581/oz today. When it hits $2,000, it will be up 26.5%. Let's see how long that takes. - De 3/11/2013 - ANSWER: 7 Years, 5 Months