As of this summer—in the hallowed name of theft prevention –Louisianians can no longer use cash in any transactions which involve used goods. Though it seems to have taken several months for business owners and everyone else to notice the new law, here is the motivation for House Bill 195, straight from the government horse's mouth (via klfy.com):

The law states those who buy or sell second hand goods are prohibited from using cash. State representative Rickey Hardy co-authored the bill. Hardy says, "they give a check or a cashiers money order, or electronic one of those three mechanisms is used." Hardy says the bill is targeted at criminals who steal anything from copper to televisions, and sell them for a quick buck. Having a paper trail will make it easier for law enforcement. "It's a mechanism to be used so the police department has something to go on and have a lead," explains Hardy.

Classically sketchy pawn shops are exempt from this ban on cash (though they must also keep records), but not your friendly neighborhood Good Will or rummage sale.

As Lawyer Thad D. Ackel put it at sott.net:

The broad scope of this definition can essentially encompass everyone; from your local flea market vendors and buyers to a housewife purchasing goods on ebay or craigslist, to a group of guys trading baseball cards, they could all be considered secondhand dealers. Lawmakers in Louisiana have effectively banned its citizens from freely using United States legal tender. The law goes further to require secondhand dealers to turn over a valuable business asset, namely, their business' proprietary client information. For every transaction a secondhand dealer must obtain the seller's personal information such as their name, address, driver's license number and the license plate number of the vehicle in which the goods were delivered. They must also make a detailed description of the item(s) purchased and submit this with the personal identification information of every transaction to the local policing authorities through electronic daily reports. If a seller cannot or refuses to produce to the secondhand dealer any of the required forms of identification, the secondhand dealer is prohibited from completing the transaction.

The rest of the rant/blog here.

Reason on currency. Peter Suderman on how the government is also involved in your debit card transactions.

(Hat tip: commenter and poet laureate, sloopyinca.)