Problems - Scalability. From place to place and from one level to another - Capital costs of greening cryptocurrency mining. It depends heavily on the size of the economy, as well as in the level of energy investment already in place - ROI - Confidence - Transparency - Increasing cost of mining - Particular countries' economic conditions and needs - Why would a government incentivize - Just reliying in current electricity costs would not be wise for miners - Taxes and taz credits - Like with all other commodities, what is their real cost and what is the true whole value - International agreements and country particular pledges