The scanning tool allows Wikipedia users to trace the source of millions of changes to entries on the website, including those done anonymously.
Virgil Griffith, 24, a researcher at the California Institute of Technology, created the tool, partly in response to news last year that US Congress members' offices had been editing their Wikipedia entries.
The scanner trawls the millions of edits made to the website's pages to reveal the IP addresses of the computers the changes were made from.
It uses a publicly available list of IP addresses assigned to companies or individuals, and then scours changes to Wikipedia pages to reveal all the anonymous edits made from those addresses.
So far, the Wikipedia Scanner has exposed entry changes made by representatives based at the CIA, the Labour Party, WalMart, the Mormon church and many others.
The Daily Telegraph reports that employees of the intelligence agency have been found altering the biographical information on former presidents, including Ronald Reagan and Richard Nixon.
A worker at the Labour Party headquarters has tweaked an entry on Labour Students, removing suggestions that the group was has been taken over by careerist politicians at the expense of grassroots radicals.
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