the FBI won them fair and square.
yeah, if by won you mean stolen and if by fair you mean using violence and coercion
You cannot call that stealing. If violence or threat of violence is used, it is a robbery. The FBI is a bunch of armed gangsters who robs their victims

Nah, government thuggery is so yesteryear. Today's enlightened FBI agents are well versed in social contract renegotiations. They dropped in on DPR & offered him free room & board for life in a guarded secure community, in exchange for his coins. Once they sweetened the deal by offering complimentary surprise buttsecs, Enlightened Self-Interest kicked in, and DPR handed over his private keys in exchange for the life of government-sponsored leisure and romance.
Who wouldn't?