A new national divide is emerging among states over whether to track sales by gun stores Should gun store sales get special credit card tracking? States split on mandating or prohibiting it. Beginning 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. But new laws will do the exact opposite in Georgia, Iowa, Tennessee and Wyoming by banning the use of specific gun shop codes. The conflicting laws highlight what has quietly emerged as one of...