Check out Mt. Gox, the site of what was the largest bitcoin exchange at one point, and you'll find a blank page. The site is now unavailable, and the exchange appears to be on the verge of collapse -- a number of Bitcoin companies announced Mt. Gox was planning to file for bankruptcy after technical problems and an apparent major theft. Customers have been unable to withdraw their money since Feb. 7. An alleged Mt. Gox document circulating on the Internet that can't be confirmed said the company had lost more than 744,00 Bitcoins in a theft that had gone unnoticed...