With about 80,000 people converging in Dallas for the National Rifle Association’s annual convention[1], one local restaurant decided to send a message to the flood of visitors.

“Thanks for visiting Ellen’s!” the downtown restaurant printed on the bottom of its receipts Friday morning. “A portion of this week’s proceeds will be donated to organizations dedicated to implementing reasonable and effective gun regulations. Welcome to Dallas!”

Joe Groves, the owner of Ellen’s, which serves Southern comfort food and all-day brunch, posted a photo of the receipt on Facebook on Friday, the Dallas Observer reported[2]. He told the Dallas Morning News[3] and Eater[4] that he decided to add the message after convention attendees had insulted some of his employees with racially-charged comments, which Groves called “demoralizing.”

“I’m making a list of the vile, racist, moronic conversations overheard from NRA attendees eating at the restaurant,” he reportedly wrote on Facebook. “They don’t even speak softly.” Customers allegedly asked Hispanic servers, “Do you keep your illegals in the back?” Groves told the Dallas Morning News[5], and said to black employees, “You don’t sound black, where are you from, India?”

It was a subtle but daring move in a gun-friendly city packed with even more gun enthusiasts than usual. And it didn’t take long for the NRA to notice.

In a message to its more than 666,000 Twitter followers Friday night, the NRA wrote[6]: “Steer clear of Ellen’s in downtown Dallas! Why go there when there are so many other great choices.”

The tweet, which had been shared nearly 6,000 times by early Monday morning, prompted a barrage of comments on Twitter and Yelp from NRA supporters calling for a boycott

Read more from our friends at the NRA