While I agree that we already have a digital currency in the idea that it's mostly transferred/handled digitally, it's only by an ad hoc system and still subject to the whims of corporations as well as currency exchange rates.
Which is why I bring up both ideas together: if the world were to trade on a single currency, there would be no transactional issues - and if the digitization of our currency came along afterward, completely replacing paper notes, it would be by design.
The difference here is that when the currency is planned/mandated to be digital, it becomes subject to the same oversight and regulation that paper notes have in America today.
But if current trends continue, the digital currency will be in the hands of banks, financiers, and other greedy interests that have already proven themselves unable to handle such a burden without bias or self-interest.
I just wanted to point out that I never signed anything, as an Undergrad at SJSU, that would waive my rights of ownership to the school. There may be a hidden clause in some legal document that we're required to read and agree to implicitly, but not as far as I'm aware.
And I bet that's along the same lines of all the hand-picked smiling seatfillers at the Olympics, or the party-line PR-sneezing government officials who would only say obscure things like "the Chinese people are proud to host the Olympics" when asked about something like Tibet.