Earlier quoted context omitted.
> In many states even unknowing possession of stolen goods is a crime I've never heard of this. Source?
Possession of stolen goods [1] is a crime USA-wide, and in many other countries. The rationale behind is ability to prosecute fences [2] - people who act as intermediaries and a layer of security between thieves and end-users, providing the thieves with option for easy cash-out. Edit: As a counter-point, at least in Poland, while obtaining stolen goods is an offense ("paserstwo"[3]), the buyer of any good or service…
"A person can be found guilty of that offense only if all of the following facts are proven: The person received or concealed or stored or disposed of items of stolen property. The items were moving as, or constituted a part of, interstate commerce. The items had a value in excess of $5,000. The person acted knowingly and willfully."
So that doesn't really answer the question asked, because it's only a federal crime if the goods are known to be stolen and a part of "interstate commerce."
Now, at the state level, this may differ. But neither of us has that information.