The real downside of wikis is that they can be edited, changed, and even redone (and twisted) by anyone from the public. And then that grudge-filled face-of-evil can sign the trusted person's name to his edited page, making the reputable person suffer as well! This is the true "evil twin" of nearly anything good that comes along. And in its wake, the wiki's credibility is compromised, because not everything in the wiki may be true.
Wikis are relatively new on the scene of technological internet choices...not everyone in the public is even aware of them, let alone the 'power' they contain. So "let the buyer beware!" When utilizing wikis, caution is the first rule of thumb. Check out your sources through a reliable source...like the reference department at your local library; they will exhaust every resource to find the correct answer for you!