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.
You are in a maze of little twisting passages, all different.