I’m surprised I missed it, but Last week Wikipedia updated all of it’s external links to use the ‘nofollow‘ microformat. This essentially means that any link from Wikipedia to a website now has zero effect on the search engine ranking of that site.

This is a big blow to SEO link builders, as one of the top authority sites on the web (Google Pagerank Wikipedia has been a great source for quality inbound links as long as the “Wikipolicia” think that your link is valid for whichever page you have added it.

Personally I think it’s a good move on Wikipedia’s part. That site’s open format makes it a relatively soft target to spammers. It’s testament to the work put in by dedicated Wikipedians that the site hasn’t descended into spam chaos. I wouldn’t be surprised to see more of the big UGC sites such as Digg following suit.

One of the sites that I manage contains an anonymous forum type of area which has been attacked by spammers in the past. Fingers crossed, it’s not been troubled for a while since we implemented a spam filter and also disallow any post containing HTML or BBCode. Since pretty much every spammer is trying to insert links in one way or another, the site just blocks their posts entirely.