tv,
Would you mind telling me exactly how, from a technical standpoint, you would even white or black list BTC?
Given that there is no such thing as a coin but just a series of inputs and outputs, what do you taint and how is that sustainably identifiable throughout the life of a "coin"?
Just make people register. That was Yifu's angle as a principle at CoinValidation. UTXO's which are not registered to a known user or entity (e.g., Coinbase or blockchain.info) would halt a transaction from being valid. Very easy to justify in the name of 'fighting terrorism and child exploitation' and whatever. You can go before congress and argue all kinds of economic mumbo-jumbo about fungibility and freedom and what-not if you like. Good luck with that.
Sharp eyed viewers might notice that if one does not register, one cannot pay one's taxes. And there are well established ways to make people pay their taxes in almost all but the most failed of states. I'll register my stash the day I'm mandated to do so (which is why my conception of the best strategy is to avoid a mandate ever being practical rather than to resist compliance after it is been mandated.)
As a function of my Coin Validation service, I'd also run a service for miners so that they can ensure that they don't waste their time mining unvalidated UTXO's as inputs and their transaction set thus remain clean. If the choice is between taking this easy and popular step of using my government chartered service, and facing shutdown of their network support and confiscation of their gear, it will be a fairly easy decision in most cases. It seems to me that the new inverted bloom filter thing it could be remarkably efficient for a miner to ensure that they are not wasting their time with transactions which are going to be legally invalid because they contain unvalidated inputs. A side benefit of using a sorted transaction set.
I also find your suggestion that the likes of Russia and China are going to change their policies and welcome crypto-currencies with open arms to be laughable.
And in case you have not noticed, piss-ant countries without nukes pretty much do what they are told by whoever's sphere of influence they fall under. Sure, there is a chance that your rosy dreams about totalitarian countries suddenly discovering the joys of individual freedom and geo-political power politics will come to pass, but I'm not betting a huge percentage of my financial statement on it.
this is exactly the sort of drivel i'd expect from your socialistic mindset. "i'd just mandate it be so".
notice that there is no depth to your assertions as they just represent your lips flapping once again. let me spell it out for you. the working assumption here is that there will be mass disobedience of your pronouncements as most ppl who are even remotely familiar with how the protocol works understands that it is impossible to "taint coins" as there is no such concept in reality. the trick for you is how to enforce your pronouncements. there are just inputs and outputs which get split & joined constantly giving "coins" that are ever lessening shades of grey as time goes by. and w/o a mechanism to identify owners of whatever unit you choose to monitor be it addresses or UTXO's, there is plausible deniability at every hop. the only way to prove someone guilty of a theft is to catch them with the private keys on their computer used at the time of the theft.