"Much of the lawlessness on blockchains is the result of a single feature: blockchains do not support reversal of improper or illegal transactions. As a result, criminals are shielded from the usual law enforcement tools, like warrants, and victims are unable to help themselves after suffering from a fraud, theft, or ransomware extortion. This state of affairs is not a necessary feature of blockchains: it is feasible to insulate digital assets from abuses by government officials and others without thwarting legitimate law enforcement or sacrificing users’ ability to enforce their own legal rights. Rather, the transaction irreversibility problem is the result of a choice by the blockchain miners."