At least with the liberty dollar you got silver or gold.
Because the folks behind the Liberty Dollar ventured inside what the Treasury considered its envelope of authority. They should have only had the weight of the bullion on the coin. Perhaps petty, but big in the eyes of regulators. Remember only Congress has the power to coin "money" and to set its value.
Bitcoin is virtual, the rules aren't as defined for it, yet, and the value is set by the market like a kind of commodity and etc.