I think it was mentioned in a throwaway manner that the title was derived from an anecdote regarding the daughter of one of Bono and the Edge's friends.
"You drank a charm to kill John Proctor's wife! You drank a charm to kill Goody Proctor!" - Betty Parris to Abigail Williams in Arthur Miller's The Crucible
I thought it was Bono's own child, but maybe not. It was something the child said at night when he or she was scared of the dark and wanted the light turned on.
Yeah-I think Berger offers the same explanation that Taymor and the U2 guys often did in interviews-a child that Bono knew would say "turn off the dark" instead of "turn on the light." The title comes from the idea that Spiderman turns off the darkness of crime, etc.
I still say that subtitle sounds like something out of a bad Jim Steinman song.
Butters, go buy World of Warcraft, install it on your computer, and join the online sensation before we all murder you.
--Cartman: South Park
ATTENTION FANS: I will be played by James Barbour in the upcoming musical, "BroadwayWorld: The Musical."