Katie's questionquestion (which, one should note, is not written seriously but precisely as a test question intended to establish policy) brings up this topic. There are a lot of mathematics websites out there, and as the blog Good Math, Bad Math demonstrates, a lot of cranks out there. MO for instance has seen a few of them, though I won't link to them. There remains the question of how to deal with them; we are likely to get questions about squaring the circle, why the reals are countable, why Godel's incompleteness theorem is false, etc. Preferably, these won't keep showing up on the front page.
Does anyone want to comment on this matter, so that we can have an official policy written here on meta?