Here in the UK, HMRC see crypto-currencies as another source of revenue - income derived from trading is subject to income tax, and of course the profits are subject to Capital Gains tax.
But of course you can't pay the tax with the cryptocurrency. Make a million from Bitcoin and you've still got to pay your 40% or whatever in actual pounds...
Tax collection is perhaps the authorities main fear rather than ‘criminal activity’? If you did make your million and it resided in your super secure offline ledger then they might have difficulties taking their cut, in pounds. As crypto payments become more common collecting taxes from offline and P2P transactions might become a nightmare.
