Promoters of a digital currency allege that it would cause a drop in criminal and illicit activity. That may be correct, or people may simply resort to another medium of exchange or barter. Philosophically speaking, virtue is not possible without the freedom of choice. If people can't choose to misbehave, it does not make them virtuous. A society in which nobody has the freedom to misbehave is far more horrifying than a society where people actually misbehave.