Ok, that estimate is two years old, but still, huge
In the course of reading Chris Anderson's new book, Free: The Future of a Radical Price (Hyperion, $26.99), for a review in an upcoming issue of VQR, we have discovered almost a dozen passages that are reproduced nearly verbatim from uncredited sources.
... Most of the passages, but not all, come from Wikipedia.
Real Users never know what they want, but they always know when your program doesn't deliver it.