Yesterday, the Senate Committee on Homeland Security and Governmental Affairs held a hearing on the potential risks, threats and promises of virtual currencies. Later today, a Senate Banking Committee will hold a similar hearing. The focus is on Bitcoin, a virtual currency that operates completely outside of U.S. financial regulations and protections. Critics argue the current lack of oversight offers anonymity to those hoping to skirt U.S. laws, but others say it’s a frontier in electronic commerce with important consumer benefits. Diane and her guests talk about Bitcoin and the future of virtual currencies.