Various versions of this clip are circulating around the Bike Blog-O-Sphere. Apparently, during a Critical Mass ride in Brazil last Friday, some crazed motorist plows through the bike procession. Totally insane. Be warned, the footage is a bit graphic. Especially if you're a cyclist.
Agree or disagree with Critical Mass rides, nothing warrants this type of response. The person driving the car, who left the scene, should be charged with attempted murder. From the reports I've read, amazingly no one was killed, but a few were seriously injured.
No real positive way to end this post. I just hope the people fully recover from their injuries, and the freak driving the car gets fully charged with something as serious as the offense.