 A new law goes into effect Monday in California requiring credit card networks to provide banks with special codes that can be assigned to gun stores to track their sales. Proponents hope this will help financial institutions flag suspicious gun-related purchases to law enforcement. But the issue has become partisan. New laws in Georgia, Iowa, Tennessee, and Wyoming do the exact opposite. They ban the use of specific gun shop codes, saying it could lead to unwarranted suspicion of gun buyers.