Wikipedia's Double Standard On Nofollow Rule
Apr. 30, 2007 at 10:04am Eastern by Barry Schwartz
Techcrunch discovered that Wikipedia was giving special treatment to their own properties, in terms of using standard, non-nofollowed, links to Wikia, "Wikipedia’s for-profit spin off."
Back in January, Wikipedia nofollowed all external links from the site, in an effort to reduce Wikipedia spam. If you visit the Wikipedia page on Wikia, you may notice some external links do not contain the rel="nofollow" attribute. Techcrunch calls them out for it.