Hi Suppose that digital cash becomes easy enough to use and becomes the mainstream medium in most [or at least many] economic transactions. The question is, how can the government TECHNICALLY collect taxes? I do not mean to start `libertarianism vs. socialism' discussion, I am more interested in the technical aspects of tax collection when transfers of money are protected by strong crypto.. Let's say, maybe this tax would work: every time someone verifies that a piece of digital cash is valid, s/he has to pay the government a little percentage of the amount. Since digital banks are easier to control than other participants of the market, this kind of tax legislation is easier to enforce. Of course these banks may be offshore, and then such collection becomes problemstic. Another alternative that I see is property taxes and poll taxes,or taxes on some commodities such as oil. But incomes seem to be hard to track. What else? - Igor.