PPPSS. (Previous Poster's Point Still Stands). You could have cash buried in the desert and the IRS wouldn't be able to take it. Bitcoin is a way with both advantages and disadvantages to hide money, but it doesn't teleport you to another plane of reality where you're immune to the violence of the state.
That's happened in several high profile bank robberies. In one robbery (I think it was a robbery on a airport hanger where they robbed an armored car company) they guys went to jail and they have some $18 million or so split between four dudes.
Even after trial, conviction and sentencing, the court reporter said the Feds still weren't able to recover around $5 million of the total money and have no idea what happened to it.
