There is a nice bit in Lee Strobels "Case for Faith" where he quotes Peter Kreeft,
“On my door there’s a cartoon of two turtles. One says, ‘Sometimes I’d like to ask why God allows poverty, famine, and injustice when He could do something about it.’ The other turtle says, ‘I’m afraid God might ask me the same question.’ "
(Admittedly I dont think this was the picture on the poster, or even that he was refferring to the Ninjas. But they are the only vocal turtles I know and perhaps this is a poignant opportunity to honour and conjur up fond memories of these heroes in a half shell. Turtle Power.)