In this blog, I have been primarily discussing private-law issues. But regulatory issues are no less important.
As public blockchains are borderless, activities on them may have to comply with regulations of multiple jurisdictions. The task is often difficult because of the diversity of regulatory approaches. One way to streamline and rationalize the regulations would be to move away from entity-based regulations (regulations based on the types of entities regulated) to activity-based regulations.
Here is my tentative compilation of blockchain regulatory issues classified according to the types of activities. It is not intended to be exhaustive. The lending and deposit-taking of cryptocurrencies, for example, are not included. An ICO (Initial Coin Offering) will involve both (1) Exchange with other tokens or fiat currencies and (5) Crowdfunding. (7) The trading of CBDC (Central Bank Digital Currencies) is not yet a reality but may come about at some point in the future.