WikiScanner automatically compares the IP address logged when someone makes an anonymous Wikipedia edit to a public database of IP addresses belonging to all sorts of corporations and government bodies. Among those that allegedly have been polishing their entries are Wal-Mart, the world’s largest retailer, voting-machine company Diebold, ExxonMobil, the CIA, the Vatican, and a slew of other companies. WikiScanner cannot identify the individuals altering Wikipedia articles, though.
"Technically, we don't know whether it came from an agent of that company, however, we do know that edit came from someone with access to their network," said WikiScanner creator Virgil Griffith. "If the edit occurred during working hours, then we can reasonably assume that the person was an agent of that company or was a guest that was allowed access to their network."
Wired News has published an interesting list of the "Most Shameful Wikipedia Spin Jobs," where users can add their own findings or vote on existing ones.