“Uh, did you sell those bitcoins, like I suggested?” Your roguish economist has four sons. Several of them invested in the virtual currency Bitcoin. They thought it was the money of the future. “Watch out,” cautioned their father. “Governments always try to look into the future and prevent it from happening. And this is a future the feds are especially keen to stop. They have a monopoly on money. And there is no way they’ll give it up without a fight.” Yesterday brought news that the fight had begun.