To begin with, the Bill of Rights gives us a guarantee in Article IV that we cannot be subject to any search or seizure without a warrant. In addition, Article V prohibits the federal government from taking our property without compensation.
Perhaps he is using the trading with the enemy act. Only problem with that is it only applies in wartime. Unless Congress has declared war and nobody told the nation about it. If not, then that law doesn't apply.
Oh, that's right, he gets to make up laws as he sees fit. Except the Constitution says only laws passed by both houses of Congress and signed by the president are laws. So he doesn't have that power.
But then his mouthpiece in residence says the Constitution is antiquated and obsolete. If that is so, then we are back to what we were before the Constitution was enacted. Instead of 13 independent nations or states, now we have 50 independent nations. Each capable of running the portion of the former federal governments courts, military and other functions as their citizens see fit.
I think the first order of business for the various governors is to round up the present administration and turn them over to the international court for trial as war criminals. Their second order of business then is to send representatives to decide if they want to form a joint government and what powers they are willing to give it.