If they want some old documents
How about the Quartering Acts of 1765 and 1774? Those acts passed by Britain were among the factors that led to revolution in the US. It seems the colonists didn't like being forced to put up British soldiers in their home.
The idea that it is some sort of settled law that US citizens have a duty to help police investigations wouldn't go very far with those who wrote the Declaration of Independence and the 3rd amendment of the Constitution! Especially once they reveal it is based on English law from before the first white man (or rather first white man who had a decent publicist) set foot on American soil.
Biting the hand that feeds IT
