The change in policy by Visa, Mastercard, and American Express was celebrated last week by gun control activists as a way to flag suspicious sales, but the attorneys general argue it misses the mark when it comes to public safety and targets gun owners, the Wall Street Journal reported on Tuesday.

“Categorizing the constitutionally protected right to purchase firearms unfairly singles out law-abiding merchants and consumers alike,” the attorneys general from 23 states wrote in a letter to the credit card companies.

Gun control advocates have pressed the financial industry to play their part in helping rein in mass shootings.

Gun rights groups have argued that the new code system punishes gun buyers and infringes on their Second Amendment rights.