In a system run by people, the transaction could be reversed, traced, and the culprits eventually brought to justice. In a system run by algorithms, designed to avoid oversight by people (governments), there is no such powers. There's no reversal. There's no checking the name on the account the transfer was to. It's just gone. I do not understand why people who have legal intentions would want to be part of the crypt…
However, there is a physical limit, pretty damn hard to run off with half a billion worth of paper notes.