What's unique about the virtual currency bitcoin, besides being relatively new, is that it is owned by no one. There's no government issuer, no bank monitoring, no transaction fees, no restrictions to creating new services, no need, even, to use your real name. Both the system and its eponymous currency exist almost entirely online. (EPA/LIU XINGZHE/CHINAFILE) Much of bitcoin's allure comes from its intense level of decentralization.