First of all, I'm part of the apparently small minority (if existent), that is not totaly abandoning the state as a concept.
The state could try to convience you to give out an "official" bitcoin adress where your payroll and any financial transaction of reasonable size could be tracked to collect VAT and other taxes. These "official" adresses would be mandatory to be stated in any contract and receipt.
Once received with a official adress it would be as hard to get your coins out of sight as it is today to launder your money the traditional way.
I do not like the imagination of such a concept but I rather prefer it to a total capitalism.