A few years back I traveled to New York to visit Ground Zero and see some concerts. I took a tour through Rockefeller Plaza, where they produce Saturday Might Live and saw the set. The tour host told our group that the only person banned from the building was Sinead O'Connor for ripping up a picture of the Pope on SNL. Sinead said she did it to draw attention to child abuse within the church.
From the BBC article -
After Christian fundamentalists claimed that a line in the title track of their 1974 album Eldorado sounded like “He is the nasty one – Christ you’re infernal” when reversed, the Electric Light Orchestra inserted a deliberately backmasked segment into their next album. Denying that Eldorado contained any subliminal messages, ELO went on to record Fire on High with an opening line that, when played backwards, says: “The music is reversible but time is not. Turn back. Turn back. Turn back. Turn back.” They released an entire album full of reversed vocals in 1983, called Secret Messages: the final track contains the backmasked message “thank you for listening”.