A class-action lawsuit has been filed against the Mt. Gox Bitcoin exchange and its owner Mark Karpeles, seeking damages in the hundreds of millions of dollars and the return of bitcoins to users whose accounts were frozen on the site. The lawsuit lays out a number of claims against Mt. Gox, chief among them that the exchange did not keep users' bitcoins securely stored or adequately detect a theft of those coins. When the online exchange figured out what was going on, it clouded the truth by telling customers there was a computer glitch, the lawsuit claims.