WikiScanner creator Virgil Griffiths created the online tool to see what people and organizations are up to when editing Wikipedia. ((Jake Appelbaum))

Wikipedia touts itself as the "free encyclopedia that anyone can edit," but a new online tool now makes it harder forthose with an agenda to edit it in a sneaky fashion.

OrdinarilyWikipedia allows anyone to edit its articles, and the encyclopedia has become a target for vandals, revisionists and spin doctors. In an effort to keep Wikipedia more honest, U.S. graduate student Virgil Griffiths created WikiScanner, a site that can trace the IP addresses of computers that have made edits to Wikipedia entries in the last five years.

While WikiScanner cannot identify the specific people making changes, it can locate the exact computer the changes came from. Thishas led to embarrassing exposures for some political parties and other groups — which is exactly what creator Virgil Griffiths had in mind.

"[I want] to create minor public relations disasters for companies and organizations I dislike," he wrote on his website. He also wants "to see what 'interesting organizations' (which I am neutral towards), are up to."

His site shows that some organizations are up to quite a lot on Wikipedia. While many Wikipedia edits are simply factual corrections or spelling and grammar fixes, some use the encyclopedia to trash political rivals and companies or excise unflattering details about themselves.

Thepractice extends to Canada as well, as many such changes can be traced back to Canadian government IP addresses. The site shows edits to articles originating from computers in government offices, including the House of Commons, Environment Canada and the Department of Foreign Affairs.

Over 11,000 changes to Wikipedia articles, including major edits to articles about parliamentarians, were discovered through use of WikiScanner, according to a Globe and Mail article Thursday. One such example showed the article on Paul Martin, which was edited to read "Paul Martin was the worst Prime Minister in Canadian history."

But Canadian examples may be among the most tame. Wired magazine has already compiled a list of "salacious edits." Among the more notable on the list: a user at Exxon-Mobil pooh-poohed the environmental impact of the Exxon Valdez oil spill; an FBI computer removed aerial images of Guantanamo Bay; and someone using a Reuters IP address called U.S. President George W.Bush a mass murderer.

Griffiths said his project is not intended to eliminate anonymity, but rather to preserve Wikipedia's credibility.

"I do not believe something like WikiScanner, which identifies people, is necessary. Overall — especially for non-controversial topics — Wikipedia already works," he writes. "For controversial topics, Wikipedia can be made more reliable through techniques like this one. For any sort of 'open' project, I strongly prefer allowing people to remain anonymous while also doing various back-end analyses to counteract vandalism and disinformation."

Wikipedia founder Jimmy Wales obviously appreciates the effort.

"It is fabulous and I strongly support it," Wales told the Associated Press.

With files from the Associated Press