 Not a crime. ABC's Stephen Portnoy. Dueling laws regarding gun sales. Starting on Monday, a California law will require credit card networks like Visa and MasterCard to provide banks with special retail codes that can be assigned to gun stores in order to track their sales. Meanwhile, states like Georgia, Iowa, Tennessee, and Wyoming have outlawed the special codes. Some Democratic lawmakers hope the retail tracking codes can help financial institutions flag suspicious gun-related purchases. I'm Mark Remillard, ABC News.