The fact that they are faceless makes it absolutely impossible to catch them, and also kind of impossible to recover stolen funds from them - they are very professional (if I should use that word).
Such an amount stolen in coins can't be recovered just easily as you guys thinks, even the one that was sent to centralised excahges, may have hard time being recovered because some of the policies of those centralised excahges cover's the protection of users right as regards to deposites, so not just that easy, there must be legal procedures and court orders for such accounts to be frozen.
So metawin have alot of hard work to do, in trying to recover theo stolen $4million, because majority's of that transactions where sent to personal Wallets which could be very hard to track.