During The Who's 1969 Woodstock performance, activist Abbie Hoffman seized the microphone to deliver an impromptu protest regarding John Sinclair's ten-year prison sentence for drug possession. Hoffman used the massive festival audience as a platform to advocate for Sinclair's release, a member of the White Panther Party, and to encourage attendees to channel Woodstock's momentum toward supporting incarcerated individuals and expanding civil liberties.

The incident has become legendary largely through accounts describing guitarist Pete Townshend assaulting Hoffman with his instrument, a story Townshend has denied while insisting he would have responded identically to any stage intrusion. However, Hoffman's later autobiography presented a markedly different version, characterising the exchange as merely an accidental collision when Townshend turned around whilst tuning his instrument, and pointing out that no photographic or film evidence corroborates the more sensational rendition of events.