@drstoker "I'm curious which currencies your friend has identified as never being used for crime"... I had a chuckle at that one. His argument that was because many Cryptos are essentially anonymous they're particularly well suited. Most countries have controls over large cash transfers so criminal activity can be stopped - having to transfer through registered bank accounts, providing ID at cash transfer locations like Western Union etc.

As for making crypto go away I suppose local governments could use specific technologies to snoop on the type of data coming and going. I think about how I get an email from HBO every now and then when the new season of Game of Thrones comes out and I forget to enable my VPN. My guess is that traffic is tracked back and forth from a particluar centralized site. Could they do that with blockchain to stop specific transactions?