NEW YORK (AP) — Visa and Mastercard paused their decision to start categorizing purchases at gun shops, a significant win for conservative groups and Second Amendment advocates who felt that tracking gun shop purchases would inadvertently discriminate against legal firearms purchases.

The decision is, at the same time, also a defeat for gun control groups.

There had been hope that categorizing credit and debit card purchases would allow authorities to potentially see red flags — like significant ammunition purchases — before a mass shooting could happen.