Plan to use military forces against civilians
Story in the Washington Times. It envisions their used against "domestic unrest," and the story reports that the Administration considered using the military against Clive Bundy and his supporters, but rejected it. Interesting, too, in that the military apparently leaked the plan. When a ruler starts to lose control of his own defense forces, it's time to reconsider.
As far as constitutional authority, Article IV §4 says that the United States shall "protect each of them [States] against invasion; and on application of the Legislature, o of the Executive (when the Legislature cannot be convened) against domestic violence." I doubt the orders have a "the President, when requested by the legislature or governor of the State involved, may..." provision. But then, "we don' need no steenking constitution."