I object to Grant Thornton not distributing the DUO back to the rightful holders. Do you think lawyers are not going to just dump them on the market and line their pockets? None of the DUO disappeared in the hack, it's just that NOBODY will get a peep out of judgey-poo who isn't in the lawyer club. But I have to say that it looks like virtually nobody is interested in making a claim anyway.
I personally don't support blacklisting yobit, i think everyone knows well enough by now they likely won't upgrade and will try to rip off the users with it in their accounts, which is the justification for doing that.
The thing with cryptopia is that I'm pretty sure NZ cops seized everything and cryptopia never had the option to distribute unaffected tokens back to users. Then some assholes who were supposed to be keeping a backup ransomed the user list.
The situation is extreme. We have the ability to block them and for the holders of DUO, not having 118,000 duo get dumped on the market unceremoniously would be a good thing.
I don't think yobit really presents that much of a threat. I am writing blocklist code anyway for cryptopia, whether we add yobit cold wallets depends on whether the member of the team promoting this action can get adequate data to conclusively be certain their cold wallets are frozen.