Brixx Wood Fired Pizza waitress Ashley Johnson was pretty fired up about the couple that lingered three hours over lunch, made her work an hour past her quitting time – and then left her only a $5 tip.

So Johnson, 22, did the 21st century equivalent of griping to the kitchen staff (or the bartender down the street): She vented on Facebook. "Thanks for eating at Brixx," she wrote, "you cheap piece of ---- camper." (For the record, the $5 tip was 17 percent of the customers' bill.)

Within 48 hours, her managers came calling. They showed her a copy of her Facebook comments and fired her for breaking company policy forbidding insulting customers. A Brixx official told the Charlotte Observer she also violated a second company policy: Speaking ill about the company on social networks. According to the company, Johnson signed her agreement to these policies when she was hired.

Johnson told the Observer she apologized to Brixx – a 12-year-old company with 13 restaurants in three states – for using bad judgment. "It was my own fault," she said. "I did write the message. But I had no idea that something that, to me is very small, could result in my losing my job."

How did Brixx find out about Johnson's Facebook posting? Brixx isn't saying – and Johnson can't pinpoint the leak. She has about 100 Facebook friends (mostly high school and college friends) but her page is private and she says she doesn't add people she doesn't know to her network.

Brixx partner Jeff Van Dyke said he wasn't sure how the company learned of Johnson's indiscretions. "It's just like high school students posting stuff on their social networking sites and thinking it's not going to get back to their parents," he said. "But somehow, it does."

When negative comments about the company started appearing on Facebook, Brixx promptly posted a statement on its page: "Brixx appreciates your feedback! Please know we value our employees very much, which is why we are one of the few small restaurant companies that offers benefits. Brixx also values our customers and has a policy against making negative remarks about them."

Brixx's firing may be legal – and has its sympathizers – but the company is taking a PR hit: The postings on the company's page and on online versions of the story are overwhelmingly negative.

Lots of companies have policies banning panning the business on social media, but should you force employees never to speak the company's name on those platforms?

That's going too far, says Scott Baitinger, owner of Streetza Pizza, whose business is largely driven by social media. 

"You need the [employee] to be a representation of your brand, if you hired them," Baitinger, author of "Twitterworks, Restaurant 2.0 edition," which offers social media advice to business owners, told Restaurant News. "So social media is just an extension of the entire customer service experience."

Would Baitinger have fired Johnson?

"Probably not,' he answered. 'I probably would have had her deal with it on her personal space differently."