You don't want to run uncontrolled and high risk experiments in large cities first, given the number of people who would be negatively impacted if things go wro

You don't want to run uncontrolled and high risk experiments in large cities first, given the number of people who would be negatively impacted if things go wrong. And in this case, with cryptocurrencies involved, it is more a case of when rather than if things go wrong, given all the potential points of failure, e.g. price crash or theft or state sponsored attack or coding error or whatever.