A very quick search for "largest cash seizures" shows a couple in the $200-300M range. In both cases, the authorities found and seized the physical cash. I don't see any precedent for someone handing it over.
I wonder what made this situation so different. Is it the illiquidity of Bitcoin at that scale? Or did Hacker X just not retain a lawyer/know what to do?
Having a BTC wallet is one of the only ways to have a billion dollars and zero institutional power, so the money is little help here. The US government is also heavily incentivized to come down hard on these sorts of people because they’re threatening the dominance of the US dollar.
Giving that money straight to the feds in exchange for immunity might be more attractive than trying to hide the reason you became a billionaire.
What strikes me about these people is how they can't stop and cash out. They risk to lose their life to jail yet don't have an exit plan. They just continue gambling.
The USA government can easily launder 1 G$ in bitcoin and give you part of the profits; it's not clear who else could. The only alternative I can imagine is some giant money laundering scheme with some authoritarian state, probably involving the smuggling of oil, diamonds and/or weapons.