Reply #11: Article I, section 8

[Occam Bandage]

"The Congress shall have power...to make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this Constitution in the government of the United States, or in any department or officer thereof. "

Article III, section 2
"The judicial power shall extend to all cases, in law and equity, arising under this Constitution, the laws of the United States."

Those, combined, pretty much let the Federal government do whatever it wants. I mean, Treason is the only crime mentioned in the Constitution, but it's not like that's the only crime the Federal government prosecutes.