The Secretary of the Treasury is authorized to prohibit and prevent the transportation in any vessel, or upon any railroad, turnpike, or other road or means of transportation within the United States, of any property, whatever may be the ostensible destination of the same, in all cases where there are satisfactory reasons to believe that such property is intended for any place in the possession or under the control of insurgents against the United States, or that there is imminent danger that such property will fall into the possession or under the con