In 2009, the mysterious and pseudonymous Satoshi Nakamoto launched Bitcoin, the world’s first online cryptocurrency. Backed by no government or hard assets, the currency’s value has skyrocketed and plunged repeatedly. A diverse group of entrepreneurs, businesses, and would-be money launders has followed Bitcoin’s trajectory avidly. The receptivity indicates a real demand for an Internet-centric medium of exchange, without banks and without fees. Yet the rise of “criminal eBays” like the Silk Road, which allow for the anonymous purchase of illegal items with the cryptocurrency, have also brought the digital cash to the attention of government authorities. Beyond monitoring illicit activity, should regulators have a role in this new financial system? Could Bitcoin—or another cryptocurrency—become a universal alternative currency? Will we ever be able to use a cryptocurrency at our local bodega?