In all of this, let's not forget that this is probably the first time in human history when mere peons can observe each and every move of government's millions. And not just "results audited by someone considered trustworthy", but unfalsifiable transaction records.
Pretty soon you will be able to see exactly where donations to charity or political campaign or your local "save debby" fund have gone. This is what's really amazing in all of this.
I suspect this will be the reason why "powers that be" will ultimately want cryptos shutdown: the openness.
Illegal uses of cryptos is just a scarecrow, long term, no matter how complex it may seem now, most of the illegal transactions will be unraveled. The ledger is public and "eternal", all that can be found will be found eventually... unlike for traditional fiat.
The ledger cannot be used to catch people through illegal transactions.
Let's say I buy bitcoin from local bitcoins, are you responsible for it's origin?
That would be the same as getting caught with a hundred dollar bill that was once used in a cocaine deal.
