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.
"I've seen the forgeries I've sent out." -- John F. Haugh II (jfh@rpp386.Dallas.TX.US), about forging net news articles