Sometimes used in reference to ? and The Mysterians, the original sixties garage band from Michigan. Their song "96 Tears" topped the mid-sixties music charts and is now considered a classic garage rock anthem.
Their lead singer, formally known as Rudy Martinez, was a really nutty guy who legally changed his name to question mark(?) and thought he was the messiah of an alien race from the future.
? is a loony, but their music is good.