But see how nice having a blacklist is (which you seem to say is the core business of banks, when in fact it is to provide massive amount of capital as loans at a cost or create yield-producing aggregated products - which can work with any currency, crypto or not, and which Tether barely fits the definition of).
I d propose every chain to have a blacklist mechanism, temporary if you want, with a voting mechanism to remove innocents. You cant facebook your way ("we re just a platform") out of financial rules or you ll just end up rewarding thieves while benefitting innocents very little.