(1)
Don't know how true this video is. But if it is authentic, then it adds another ugly incident to this already sorry war.
http://news.yahoo.com/blogs/envoy/pentagon-condemns-alleged-marine-misconduct-graphic-video-170756596.html

(2)
Well, it turns out that the above video is authentic and all the marines in it have been identified:
http://abcnews.go.com/Blotter/us-marines-urinating-video-identified-charges/story?id=15353762

(3)
From this article, I get the impression that incidents like this are not isolated cases and the military knows about it but did nothing to stop it, just like the prison torture case that happened in Iraq a few years ago. They not only didn't stop it but lied and tried to cover it up when the incident was revealed and made known to the public.
http://news.yahoo.com/outrage-video-marines-urinating-taliban-corpses-veterans-view-055500933.html