I have written here before about Wikipedia, the on-line encyclopedia written and maintained by anyone who wants to contribute. The wonder is not that it works so well but that it works at all. And work, it apparently does. It has been found to be generally as accurate as the Britannica.
Some years ago, I wrote a Boston Globe column that contained three spoof letters, one of them purportedly from Henry Oldenburg, Secretary of the Royal Society, London, to Antony van Leeuwenhoek, Delft, Holland, 20th of October, 1676. The column was clearly flagged as a spoof.
The letter showed up in the Wikipedia entry for Leeuwenhoek, accepted as authentic, generating a bit of an on-line to-do. The Royal Society archivist was consulted, and the letter was finally traced to me. I confirmed the spoof.
I was surprised that anyone might have taken the letter as authentic, but impressed at the self-correcting character of the wiki concept.