The Islamist terrorist group Boko Haram has been in the news lately for kidnapping girls in Nigeria and then threatening to sell them as slaves (link).
The usual explanation of the group's name is that it means "western education is a sin", and many might assume that "boko" is from the English word "book". That folk etymology is wrong, but it didn't keep Wikipedia from misleading about their name for years.
If you've visited Wikipedia in the last five years, you might have heard about the "Bicholim Conflict of 1640-1641 [which] was a period of armed conflict between the Portuguese rulers of Goa and the Maratha Empire led by Shivaji Bhonsle in the northern regions of Goa [India]".
Except, none of that ever happened: the "Bicholim Conflict" was completely fake, a hoax created by an unknown user.
This is the Bicholim Conflict article that Wikipedia deleted after taking over five years to realize it was a hoax. It's the version as of October, 2010 and retrieved from this.
Date Mid 1640 - early 1641
Location North Goa - particularly in region of Bicholim, Pernem and Bardez
Result Treaty of non-aggression
Since March 2009 , Wikipedia has had a variant of this smear of the Minuteman Project ("MMP") on their Vigilante entry:
The Minuteman Project has been described as vigilantes dedicated to expelling people who cross the US-Mexico border illegally.
Since that quote was added, Wikipedia has backed up its claim with two highly questionable sources, as will be described below.
First note that the same Wikipedia page gives a different treatment to other groups:
One of the reasons why Wikipedia appears at or near the top for most search terms is because people keep linking to them (another reason is almost assuredly due to search engines promoting them to the top).
If you realize why Wikipedia should be opposed, but you still need to point to a WP article on your site, you should never under any circumstances give WP a "regular link".
A "regular link" means something like:
<a href="http://wikipedia...">some Wikipedia article</a>
On June 15, 2011, Thomas James Ball immolated himself in front of the Cheshire County (New Hampshire) Superior Courthouse in a protest over men's rights. A story from the Union Leader is here, and a site constructed about the event is here.
For years, Wikiquote has been smearing Rush Limbaugh by falsely pretending that he said the following (en.wikiquote.org/w/index.php?title=Rush_Limbaugh):
You know who deserves a posthumous Medal of Honor? James Earl Ray [the confessed assassin of Martin Luther King]. We miss you, James. Godspeed.