I'm going through wikipedia checkin' some stuff out and i'm reminded of something I read about wikipedia using rel="nofollow" in their links. So, I checked it out and they do use the nofollow. They even use it in the references. This blows because wikipedia is using those sites to give themselves a little credibility and not to mention uses the information off those sites to add to its content, but it won't even give them a legitimate link in return. That is like your waitress bringing you a cold beer with a chilled glass and all you do is say thanks and then stiff her on the tip.
Well people spam thier links so they cant help it i guess.. even a reference link can lead to good amount of spam for such a high traffic site. they could maybe modify thier system like if a link is there for a period of 30-60 days without bieng modified it becomes a do follow link
What I don't like about Wikipedia is all of that information at the mercy of certain individuals who control all that knowledge and influence. We need more resources not less.
well no matter its nofollow or dofollow...the amount of traffic it can deliver is what makes its worth