Today there was an issue in wikipedia, globalwarming awareness2007 websites have been blacklisted from wikipedia, because one of french SEO contestant spammed wikipedia.

He took the links of french competitors on SEO World Championship and created a wikipedia webpage with those links.

As a result, the Wikimedia board has decided to use "nofollow" attribute for all external links of Wikipedia. You can read a following discussion among Wikipedians about the decision:

«Having been requested by Jimmy to do so, and having seen a fun rumor of a "search engine optimization world championship" contest targeting WP[1], I’ve gone ahead and switched rel="nofollow" back onto URLs in en.wikipedia.org’s article namespace.»

More informations : SEO World Championship 2007 blacklisted websites and sandboxed globalwarming awareness2007 websites on wikipedia

Screenshot :

All seo contestants websites have been blacklisted, our site is also blacklisted and we don’t like that, we never have spammed Wikipedia and we will never do that.