Grant's determination to protect the financial interests of Led Zeppelin was also reflected by the sometimes extraordinary measures he took to combat the practice of unauthorized live bootleg recordings. He is reported to have visited record stores in London that were selling Led Zeppelin bootlegs and demanded all copies be handed over. He also monitored the crowd at Led Zeppelin concerts in order to locate anything which resembled bootleg recording equipment. At one concert at Vancouver in 1971, he saw what he thought was such equipment on the floor of the venue and ensured that it was destroyed, only to later learn that it was a noise pollution unit being operated by city officials to test the volume of the concert. On another occasion, at the Bath Festival in 1970, he threw a bucket of water over unauthorised recording equipment. Grant's famous dressing room scene in the film "The Song Remains the Same" (1976), where he demands an explanation from concert staff about the sale of illegal posters, was typical of his no-nonsense dealings with people who tried to profit at the band's expense.