BBC:-Four women in Southern California were asked to prove they were legal residents by a waiter in a restaurant.
Managers of Saint Marc, in Huntington Beach, later apologised and said they had fired the staff member.
The original Facebook post about the incident has been shared more than 1,000 times and gained hundreds of comments.
But the women have also received a backlash from people dubbing the story “fake news”.
Diana Carrillo, who has Mexican ancestry, told the BBC: “I’ve never faced discrimination like this in the past. The four of us who went to the restaurant were all born in the United States.”
The incident happened when they visited the restaurant on 11 March.
Ms Carrillo said: “As soon as I sat down, the waiter approached the table and without welcoming us, asked me for my proof of residency.
“I just handed it over to him. I didn’t know what to say. I had no words. I felt paralysed literally for a few moments, just in a complete state of shock.”
She said the waiter then asked her friends and sister the same thing, adding: “I have to make sure you’re from here before I serve you.”