I don't see the surprise here... we all knew that this stuff is happening, and seeing a video of it should only make it worse if you didn't care before or were ignoring it (unless you really didn't know people are getting beaten up... in which case it's a combination of both.
The really interesting part to it is whether people seeing it will step in or not. Everyone's always talking of how horrible that stuff is, but I'd bet my ass that 90% of all the politicians, teachers, forum posters (yes, that's you) oranyone else would cover their own asses and look the other way before even thinking about helping. Interestingly, compared to all of these people, the few taking a video of it actually do quite a lot to stop shit like that from happening, don't you think?