Let`s us say that a exchange got hacked, Would there be anyway to ban those bitcoins? like blacklist the stolen coins so they cannot be used on the network? I know about going back in time with consensus of the network to a earlier block or forking and using that new chain, but could you just not ban the stolen coins? I mean make a way to do that?
I don't think it's possible, the culprit can create new address again and again and he can use a mixer, there is a lot of that here, and upload it to exchanges, there are a lot of possible ways for the culprit to get away, but it is a very huge amount, the idea of a fork is possible, but not highly recommended.