Nouriel Roubini is right on here.
Crypto-curriencies are not only just an artificial, unnecessary and truly nonsensical commodity, but the peculiar functions that it can only serve is opposite of what is seemingly and expressly intended and implied in multiple and various ways; basically, if the Parties of any transaction/trade want to settle with a crypto-currency, that's fine, if that makes sense to and is agreed by the parties. If a dispute were to ever arise, hopefully the transaction will be valid somewhere for legal arbitration and settlement; for that to be the case, it has to be relative to something and/or everything, as everything is relative; further, you always have to exchange something for the crypto-currency and it must be exchanged and be relative to something and/or everything for it to be of any use/value; it's just a peculiar, nonsensical, commodity; it's not a store of value and it's not money. Further, in order to be a commodity that makes sense, it would need to be valid, effective and enforceable for the use, trade, valuation and pricing of negotiable instruments and be usable and effective as valid and acceptable Collateral for Trade, which could be hypothetically and theoretically possible only through a reliable, trusted crypto-Escrow/Trust system that's acceptable to and accepted by all Parties, and that serves all inherently necessary and essential purposes and functions as a real instrument of Trade. This is just from a natural, inherent and true economic and trade standpoint.
Otherwise, and in general, there's very many disturbing, unfortunate and inherent implications of and from and attributes of crypto-currencies.
How do crypto-currencies make any sense as an alternative to banking, when real banking literally, truly and inherently exists for the purpose and support of real Trade? What's really needed and is lacking the most in the West and most especially and extremely in the U.S., and is also needed throughout the world, is just real, global banks to provide real service for real Trade for more than the top, few politically connected Elites that are effectively one with both government and the banks, which are essentially and effectively one and the same.
Maybe the inevitable time for the Federal Reserve to be placed in a public Trust is now, as either all the banks and entire public banking system will need to go into a public Trust OR every American citizen and/or person will need a Trust in order for natural, individual economic Sovereignty to be attained. The natural and necessary individual economic sovereignty meant and intended under and through G-d, is naturally, inherently and truly a matter of Trust, not a matter for crypto-currencies to be any sort of solution for.
The idea that it makes sense to have a privatized, public banking system is truly quite nonsensical and absurd. Additionally and further, having privatized means of production together with a privatized Central Bank, both controlled by the same ruling Elites that also control the government, is very unfortunate and extremely oppressive.
IN G-D IS OUR TRUST, OUR EQUITY, OUR BOND, OUR DEED, OUR TRADE, OUR SOVEREIGNTY, OUR FREEDOM!