If a chemical plant sets up in an area then pollutes the environment during the course of business, it is required to clean up the mess. Known risks are required to have mitigations ready, and sometimes-expensive procedures must be followed to ensure safety.
Bitcoin (and everything like it) is very much at the "Pollute the environment with whatever the hell I want" phase of its existence. That should change.
Bitcoin should be taxed to recover the externalized costs it imposes -- basically, compensate the victims of bitcoin-enabled crime.
Is only a small fraction of bitcoin usage related to crime? No problem -- the tax will be very low.