Feds are eager to exchange a bitcoin haul seized from the leader of an opioid drug operation because they are worried the digital booty could devalue at any moment. The US government seized more than 513 bitcoins and 512 Bitcoin Cash from Aaron Shamo last year after arresting him for selling synthetic pharmaceuticals containing fentanyl on dark net markets. Shamo was also busted with 500,000 pills and $1 million in cash stuffed into trash bags, according to authorities.