During The Who’s set at Woodstock, Abbie Hoffman took to the stage and grabbed Pete Townsend’s microphone, and just as he was in the middle of yelling, “Free Rubin Sinclair”, Townsend “El Kabonged” him over the head with his SG.
Prior to the event, the Yippies and the Black Panthers blackmailed the backers of the original Woodstock Festival for $10,000 and booth space (they threatened to slur the event and cause physical problems before/during if their demands were not met).