What tools do policymakers have at their disposal?

As governments weigh the pros and cons of cryptocurrencies, they often reach different conclusions. Policymakers are in the early stages of determining how best to interact with cryptocurrencies, with current responses ranging from declaring them illegal all the way to actively fostering their development. There is a wide range of tools at the disposal of the authorities, but also some unconventional constraints. Given the decentralized nature of most cryptocurrencies, there would be benefits from global coordination of legal and regulatory treatment, but there is clearly not a global consensus among policymakers.