Personally I can't see how they can regulate me sending you a file that has a hash code or something similar in it. just an ascii text string that happens to connect a block chain that means my $2 is now yours.
They can try & stop it &/or tax it.....but I can't see how. I'm sure they will come up with 'rules' &/or arrest people (eg in india?) but this crypto horse has bolted IMHO !!
So no tax, no banks..... ummmm
the world is going to be a very different place :-)