Wikileaks busts Gitmo propaganda team who were apparently editing wikipedia and trying to influence digg and other "social news" sites.
The part that scares me is that this is probably happening all the time. And unless you've adopted a page and made yourself responsible for it's content you probably wouldn't notice.
There should be a way to rate changes to an article. Maybe like a digg system, as long as captchas are still effective we can keep bots out (unless they're owned by wikipedia..) and then we only have to battle other people. And while people will do a lot for money there's only so much they can do. I still have to believe there's more people willing to do good.