Snopes says that was false.....it was a law that was aimed at thieves trying to sell stolen metal.
Actually, SNOPES admits that this was briefly true, but it is now false. Based on the email was going around in 2015, the claim is now false.
HOWEVER. It was true at one point. But because of the outcry, the legislature modified their outrageous legislation.
The original law passed in 2011, by Act 195.
In 2012, by Act 292, the Legislature corrected the problem.
SNOPES cites this ‘more reasonable’ article from the Consumerist in 2011.
“In order to combat the rising threat of metal theft, Louisiana passed a law that prohibits anyone who trades used property more than once a month from conducting that transaction in cash. This should cut down on metal vultures stripping down the infrastructure to turn it into money for their drug habit. However, this also means you can’t really hold a garage sale more than once every 30 days without some burdensome restrictions.
The law excludes non-profits and pawn shops. But flea markets, trading posts, and even the mom who wants to have more than one garage sale a month are caught up in the crossfire too. The new law will now require them to keep detailed records of every transaction, only accept personal check, money order, or electronic transfer, and log their customers’ ID’s.”
Here is the SNOPES link: http://www.snopes.com/politics/business/cashillegal.asp