NEW YORK (AP) — Hembert Figueroa just wanted a taco.

So he was surprised to learn the dollar bills in his pocket were no good at Dos Toros Taqueria in Manhattan, one of a small but growing number of establishments across the U.S. where customers can only pay by card or smartphone.

Cash-free stores are generating a backlash among some activists and liberal-leaning policymakers who say the practice discriminates against people like Figueroa, who either lack bank accounts or rely on cash for many transactions.

Figueroa, an ironworker, had to stand to the side, holding his taco, until a sympathetic cashier helped him find another customer willing to pay for his meal with a card in exchange for cash.

“I had money and I couldn’t pay,” he said.

The issue got some high-profile attention this week when retail giant Amazon bowed to pressure from activists and agreed to accept cash at more than 30 cashless stores, including its Amazon Go convenience stores, which have no cashiers, and its book shops. Amazon declined to say when the change would happen.

There is no federal law that requires stores to accept cash, so lawmakers are working on the issue at the state and city level.

Earlier this year, Philadelphia became the first city to ban cashless stores, despite efforts by Amazon to dissuade it. New Jersey passed a statewide ban soon after, and a similar ban is working its way through the New York City Council. Before this year there was only one jurisdiction that required businesses to accept cash: Massachusetts, which passed a law nearly 40 years ago.