Lennon was suspected of planning to disrupt the 1972 Republican national convention and kept under scrutiny but an informant reassured the bureau that Lennon's effectiveness was limited "since he is constantly under the influence of narcotics".

The files also report a 1955 rumour that Marilyn Monroe may have been a Communist party member and reveal that FBI chief J Edgar Hoover thought the Doors frontman Jim Morrison was repulsive.