Did you know Wikipedia is governed by just 500 active administrators, whose real identity in many cases remains unknown?
Moreover, studies have shown that 80% of all Wikipedia content is written by just 1% of all Wikipedia editors, which again amounts to just a few hundred mostly unknown people.
Obviously, such a non-transparent and hierarchical structure is susceptible to corruption and manipulation, the notorious “paid editors” hired by corporations being just one example.
To add at least some degree of transparency, German researchers have developed a free web browser tool called WikiWho that lets readers color code just who edited what in Wikipedia.
More detailed install and usage instructions found at the WikiWho page.