That hands-off stance may have started to change this week when the feds took action against Mt. Gox, the world’s leading Bitcoin exchange. Many people use Dwolla, a PayPal-like payment network, to send dollars to their Mt. Gox accounts. They then use those dollars to buy Bitcoins. On Tuesday, Dwolla announced that it had frozen Mt. Gox’s account at the request of federal investigators. It’s the first federal action against the currency. CNet has confirmed that the asset seizure was initiated by Homeland Security Investigations, a division of Immigration and Customs Enforcement. Among other things, that agency has the power...