Sauce?
Didn't think so.
January 2018
Cryptocurrency mining is a waste of energy – IMF's Lagarde
https://www.rt.com/business/416946-bitcoin-mining-energy-waste-lagarde/
November 2018
IMF says governments could set up their own cryptocurrencies
https://www.theguardian.com/business/2018/nov/14/imf-says-governments-could-set-up-their-own-cryptocurrencies