4,000 BTC were transferred out, and 3,400 BTC were returned in the end. The remaining BTC, worth about $47 million, was taken by the attacker as a 'bug bounty.' This might be the most expensive white-hat operation in crypto history for Liquid, but it also sparked controversy: transferring the funds first and then deciding to keep 15%—does this count as white-hat, or is it another form of extortion? $47 million for a lesson on a vulnerability also brings the longstanding issues of the bounty mechanism in the crypto industry back into the spotlight.