Mystery Math Whiz and Novelist Advance Permutation Problem
The article doesn't focus much on the 4chan aspect of the story, but I think it's interesting to realize that your only real currency on anonymous message boards is the quality and content of your post at that moment in time.  In the real world, or anywhere online where you have a reputation, that reputation can give you credibility when credibility is not deserved.  It also attaches an ego dynamic to everything you say, and every time you're called out.  With anonymity, that's all gone.  If your ideas stand, it has nothing to do with your reputation.  And if you're shown to be wrong, it's much easier to change your position and adjust your worldview.