How is it happened? was it stolen from the owner's wallets or the fiat money which was stole was converted to cryptocurrency? I have not really gotten your point. Money laundry is has old as human himself. If money can be laundry across boarders then cryptocurrency which also money (internet asset) can also be laundry. There is no big different between fiat and crypto when it come to stealing. But the slide different is. Fiat uses police, army and other security personals to secure the save while crypto uses seed phrase to secure their save (wallet). Fiat pays people to secure the save while crypto did not.