Tim Challies writes in his blog:

Wikipedia says that knowledge flows horizontally from human-to-human and that truth is the sum of this knowledge; the Bible tells us that knowledge and truth find their source in God and that all truth flow vertically from him to us. At the heart of the wiki model is a new conception of truth—truth is what we agree upon.

I don’t think it is always this simple. But the message should be recognized for its warning. The Shroud of Turin article in Wikipedia is pretty good most of the time. But it may change from one day to another based on how many people agree one way or another on any given day.