http://en.wikipedia.org/wiki/Backmasking
In the late 1970s, during the rise of the Christian right in the United States, fundamentalist Christian groups began to claim that backmasked messages could bypass the conscious mind and reach the subconscious, where they would be unknowingly accepted by the listener… During the same year, thirty North Carolina teenagers, led by their pastor, claimed that singers had been possessed by Satan, who used their voices to create backward messages, and held a record-burning at their church…
Some messages chastise or poke fun at the listener who is playing the song backwards… The B-52’s song “Detour Through your Mind”, from the 1986 LP Bouncing off the Satellites, contains the message, “I buried my parakeet in the backyard. Oh no, you’re playing the record backwards. Watch out, you might ruin your needle”… The band Mindless Self Indulgence released a song titled “Backmask”, which contains the forward lyrics “Play that record backwards / Here’s a message yo for the suckas / Play that record backwards / And go fuck yourself”. The backwards messages in the song include, “clean your room”, “do your homework”, “don’t stay out too late”, and “eat your vegetables”.
My generation straddles the gap between LPs and CDs, and falls squarely in the media-fuelled Satanist paranoia era. I clearly remember, as a kid, watching some fat evangelist on a news program manipulating levels on a backwards-played rock LP to make it say “we are Satan’s soldiers”, or some other such hogwash. The amount of time and effort that was wasted on such trivialities is mind-boggling.