Wikipedia

Virgil Griffith of Cal Tech computation and neural-systems graduate student created the Wikipedia Scanner. This Scanner offers users a searchable database that ties millions of anonymous Wikipedia edits to organizations where those edits apparently originated, by cross-referencing the edits with data on who owns the associated block of internet IP addresses.
Voting-machine company Diebold provides a good example of changes that are made to Wikipedia, with someone at the company's IP address apparently deleting long paragraphs detailing the security industry's concerns over the integrity of their voting machines, and information about the company's CEO's fund-raising for President Bush.
Someone with an IP address from Wal-Mart made this change:

From:

Wages at Wal-Mart are about 20% less than at other retail stores. Founder Sam Walton once argued that his company should be exempt from the minimum wage.

To:

The average wage at Wal-Mart is almost double the federal minimum wage (Wal-Mart). However, founder Sam Walton once argued that his company should be exempt from the minimum wage.

Also, politician's offices are heavy users of the system. Former Montana Sen. Conrad Burns' office, for example, apparently changed one critical paragraph headed "A controversial voice" to "A voice for farmers," with predictably image-friendly content following it.

With the Wikipedia Scanner now in effect, maybe dire changes to Wikipedia will not be made as often. Wikipedia is open to so many people with so many different views. The whole point of the online encyclopedia is that it is collaborative and multi-sourced. Wikipedia calls itself "the free encyclopedia that anyone can edit," which is another way of saying it is not fact-checked. Or spin-checked, for that matter. I would not trust it as a source for any paper that I am going to write. I do not think that Wikipedia can be trust as a honest source for anything.