== Citation needed == 

 "At Woodstock in 1969, Hoffman interrupted The Who's performance to attempt a protest speech against the jailing of John Sinclair of the White Panther Party. He grabbed a microphone and yelled, "I think this is a pile of shit! While John Sinclair rots in prison ...". The Who's guitarist, Pete Townshend, unhappy with the interruption, cut Hoffman off mid-sentence, snarling, "Fuck off! Fuck off my fucking stage!" He then struck Hoffman with his guitar, sending him tumbling offstage. Townshend later said he actually agreed with Hoffman on Sinclair's imprisonment, though he made the point that he would have knocked him offstage regardless of his message." 

 The above incident is disputed - see the Woodstock article. According to other Wikipedia articles, there is no photograph, film, or audio of this. Where is the original source of the incident? As Woodstock was widely documented, where is the documentation?