I looked up the exact text of Lousiana House bill 195, the law in question. What is does is require second hand STORES or RETAILERS, who purchase "used" items from people, to pay those people by some means other than cash, and to obtain ID and personal identification from those sellers ~ TO HELP CATCH PEOPLE WHO ARE SELLING STOLEN MERCHANDISE TO THRIFT STORES, SCRAP YARDS, etc.
The law doesn't apply to non-profit organizations. The law doesn't apply to pawnshops because there are already all sorts of laws covering pawn shops. The law doesn't apply to yard sales because those are SALES ... a person holding a yard sale isn't buying stuff from people on the street.
Whether or not this law is (a) wise or (b) legal or (c) enforceable is another story...
Thanks for calming the seas on this one!