Abbot Howard Hoffman (November 30, 1936 - April 12, 1989) was an American political and social activist, anarchist, and revolutionary who co-founded the Youth International Party ("Yippies"). Hoffman was arrested and tried for conspiracy and inciting to riot as a result of his role in protests that led to violent confrontations with police during the 1968 Democratic National Convention, along with Jerry Rubin, David Dellinger, Tom Hayden, Rennie Davis, John Froines, Lee Weiner, and Bobby Seale. The group was known collectively as the "Chicago Eight"; when Seale's prosecution was separated from the others, they became known as the Chicago Seven. While the defendants were initially convicted of intent to incite a riot, the verdicts were overturned on appeal.

At Woodstock in 1969, Hoffman reportedly interrupted The Who's performance to attempt to speak 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 ..." Pete Townshend was adjusting his amplifier between songs and turned to look at Hoffman over his left shoulder. Townshend shouted "Fuck off! Fuck off my fucking stage!" and reportedly ran at Hoffman with his guitar and hit Hoffman in the back, although Townshend later denied attacking Hoffman. Townshend later said that while he actually agreed with Hoffman on Sinclair's imprisonment, he would have knocked him offstage regardless of the content of his message, given that Hoffman had violated the "sanctity of the stage," i.e., the right of the band to perform uninterrupted by distractions not relevant to the show. The incident took place during a camera change, and was not captured on film. The audio of this incident, however, can be heard on The Who's box set, Thirty Years of Maximum R&B (Disc 2, Track 20, "Abbie Hoffman Incident").  In 1971's Steal This Book in the section "Free Communication," Hoffman encourages his readership to take to the stage at rock concerts to use the pre-assembled audience and PA system to get their message out. However he mentions that "interrupting the concert is frowned upon since it is only spitting in the faces of people you are trying to reach."  In Woodstock Nation, Hoffman mentions the incident, and says he was on a bad LSD trip at the time. Joe Shea, then a reporter for the Times Herald-Record, newspaper that covered the event on-site, said he saw the incident. He recalled that Hoffman was actually hit in the back of the head by Townshend's guitar and toppled directly into the pit in front of the stage. He does not recall any "shove" from Townshend, and discounts both men's accounts.

was anyone arrested at this point?