Since 2011, regulators have increased scrutiny on banks customers. The Federal Deposit Insurance Corp. in 2011 urged banks to better manage the risks of their merchant customers who employ payment processors, such as PayPal, for credit card transactions. The FDIC listed gun retailers as "high risk" along with porn stores and drug paraphernalia shops.

Meanwhile, the Justice Department has launched Operation Choke Point, a credit card fraud probe focusing on banks and payment processors. The threat of enforcement has prompted some banks to cut ties with online gun retailers, even if those companies have valid licenses and good credit histories.