I made a couple of suggestions: (1) that private cryptocurrencies are neither more opaque nor more dangerous to the world financial system than other collectibles of inherently limited quantity, which finance and tax law seem to be able to deal with; (2) that other regulatory schemes are analytically closely-related, and that you might want to look at the administration of the ethanol tax credit; and (3) that all the cryptocurrency privacy in the world doesn't amount to anything compared to the forms in which the world's wealthy really do their hiding and transaction-obscuring. Each of these resulted not in learning for you, but merely some shout-out in the next draft. This was unfortunate. Those were illustrations of points to think about, not tokens to be cashed in by reference.