Platonides wrote:
So if the captcha asks for 'red riding', and the vandal answers 'red penis' the Perrault's character is renamed on some book page being digitized?
I wondered that :)
I think they present the same word more than once and have a voting algorithm to decide what it really is. They don't reveal exactly how that works - presumably because they need to keep the details secret so they don't help people who want to game it.