The start is a bit of a shock, but watch the whole thing. You might not expect how it ends.
This took place on Friday afternoon, November 18. Video found on and further discussion at Boing Boing.
Update: more video from another vantage point here. The officer casually using pepper spray against nonviolent students as if he's treating his garden for aphids has been identified as a Lt. John Pike. Some folks are suggesting that in honor of his actions, the unnecessary use of pepper spray against peaceful protestors who pose no threat or resistance should be referred to as "Piking" and those who carry out such action be called "Pikers."