Credit card giant Visa has stated that it is “firmly against” any move that would make “private companies serve as moral arbiters” as it responds to investor calls for greater tracking of suspicious gun and ammunition purchases.

The September 13 statement was issued following the International Organization for Standardization’s (ISO) approval of Amalgamated Bank’s application to establish a merchant category code (MCC) for gun and ammunition retailers.

An MCC four-digit code acts as a unique identifier for grocery stores, sporting goods stores, bicycle shops, and many other retailers.

Visa argued that when it processes a transaction, it has no visibility into what items a consumer is purchasing “irrespective of which MCC applies to a merchant.”

The payments company moved to stress its implementation will only give clarity on the type of business a consumer has purchased a product from, not the goods purchased.

“We do not believe private companies should serve as moral arbiters,” Visa said. It added that asking private companies to decide what products or services consumers can purchase sets a dangerous precedent and constitutes an invasion of privacy which it is firmly against.

Visa concluded by highlighting one of its fundamental principles “to protect all legal commerce,” while upholding the privacy of cardholders.

“That has always been our commitment, and it will not change with ISO’s decision,” the statement stressed.

New York City Comptroller Brad Lander is one of many investors calling on American Express, MasterCard, and Visa to support such proposals to improve tracking.