Digital currency is to change the world, many of which were positive, to a certain extent, they pose a containment of the government, gave the people an alternative, but that doesn't mean they don't need to be regulated.
One of the core reason is: anonymous, do not track, not regulated digital currency will make form a closed loop technology crime, money laundering and terrorist, and disappear from unsolved bits, bytes, while the impact damage with each person in this world.
If every penny of extortion is tracked, is there enough motivation and courage to launch a WannaCry to attack the world?
even though now we live in the digital era, that anything can be easier and more efficient, also being able to use some features like anonymous, still we need to have a supervisor to avoid undesirable things