Things should be built or handled in a way that makes it almost impossible to sell or exchange stolen bitcoins for goods and services, otherwise their receivers will have lots of issues exchanging the coins and questions to answer. They could be arrested and investigated physically for holding stolen coins. Ofcourse, it they are not the thieves, they should be released but the coins could remain confisticated
If you own a business or render any form of service, you have the right to accept or reject any coin that you consider not to come from a legal source or linked to illicit activities that’s your call to make, but to propose that something like that should be implemented in the blockchain is the same thing as those pushing for censorship, and have you also thought about how it could be abused? Mind you, exchanges are very quick at detecting coins which come from a flagged address, so it’s not something new again.
The coldcard hack had made people come up with different ideas of security measures but that suggestion he gave is is like fighting for a worthy cause but in an unpleasant/acceptable way that would make people question his intentions for thinking such, Bitcoin in general is against censorship and coming up with an idea that encourage it is a wasted effort.
You're right Hazink, exchanges are already helping out in freezing deposits from flagged accounts so his suggestions is not very valid since it's something that's been ongoing before this recent hack that's birthing all these different suggestions. The truth is that everyone has access to use Bitcoin so people with bad intentions would also use it too.