In case the video isn't clear enough, this guy was targeted because he was a community leader for bicycle activism.

When will these guys ever learn?  I suppose once the force starts admitting people with a slightly higher IQ.  Seriously, though - for every jerkoff like this, I'm sure there are 10 guys who are more interested in doing their job than abusing the uniform.  But unfortunately, for every jerkoff like this, there are a thousand who didn't find themselves caught on camera.

Sigh.

According to BoingBoing, the cyclist (yeah, not the cop), was arrested and held for 26 hours and has been charged with attempted assault and resisting arrest.  Which may or may not be true - after all, the camera does stop rolling after the initial assault from the nice man in blue.  But from what I see in the video, anything following this attack falls clearly in the realm of self-defense.