There is too much money in circulation to switch to a cyber currency. The best alternative would be to improve the systems we already have. Make the technology more secure, more efficient, and available for all purchase locations (online and in-store). The work and reform it would take, the risks involved, and the overall benefit of it out-way updating the current system. Many people would agree they are content using a system like Paypal or the newly introduced card chip are a supplement to the current currency, but it is not a replacement. Not to mention one of the few cyber currencies, Bitcoin, can already be mined or used to launder money.