I have no doubt there are some people here that are racist against blacks. However, you're clearly racist against whites.
You can stand up against racism without defending the actions of the men in the video or placing any amount of blame on the victim.
It is totally irrelevant why the white guy was there. He could have been buying crack, looking for prostitutes, or coming from the local soup kitchen after volunteering. The guys that ganged up on him had no right to assault him and you (as a black man, I assume) should be admonishing their actions in the strongest possible terms because I'm sure your life is hard enough with the racism that still exists today without having the reasons for that racism (stereotypes, ignorant beliefs, etc.) being reinforced by the guys in this video.