There was an interesting story on NPR's Morning Edition yesterday about a historian (Timothy Messer-Kruse) who tried editing an article in Wikipedia, only to have his changes immediately reversed as soon as he made them. The article concerned the Haymarket affair, when rioters at a labor demonstration in Chicago in 1866 tossed a bomb at police and several people were killed. Evidently Messer-Kruse found some evidence that the standard version of this event, as told in history textbooks, may not be entirely correct. He thinks his attempted revision of the Wikipedia entry was reversed for ideological reasons. The Haymarket affair has been an important part of labor history, and partisans of organized labor apparently did not approve of Messer-Kruse's version of events.
The NPR story mentions an interesting-looking book that I have not seen yet:
2012 Too Big to Know: Rethinking Knowledge Now That the Facts Aren't the Facts, Experts are Everywhere, and the Smartest Person in the Room is the Room. Basic Books, New York.
The story brought mind my own encounter with this kind of ideological editing on Wikipedia, involving the entry for City. I posted the following comment on the NPR site: