McDonald's
A McDonald's customer is seen through the window at a McDonald's restaurant in San Francisco, Feb. 9, 2009. Getty Images/ Justin Sullivan

A McDonald’s employee working at a Jacksonville, Florida, outlet, was caught on video slapping a customer so hard, it threw the glasses off the latter’s face on Thursday.

The video was uploaded on social media.

Witnesses present at the fast food joint at Beach Boulevard near St. Johns Bluff Road, Jacksonville, at the time of the incident said it was the unnamed customer who prompted the altercation, Action News Jax reported.

According to one of the witnesses, the customer went up to the counter and threw a cup of coffee at an employee. That is when the employee grew angry and began abusing the customer. As to what led the customer to take such an action against the employee is not known.

The employee is seen shouting, “Did you throw that drink at me?!” in the eight-second-long video that was uploaded both on Facebook and Twitter.

Eddie Ford, another customer present at the scene, said regardless of who might have started the altercation, the employee could have handled the situation differently.

"I'm speechless. I'm blown away by that one," Ford said. "I think it's totally unprofessional. Your job is customer service, and you come behind the counter and fight a consumer? That's crazy. You're the face of the company."

Ford’s viewpoint was shared by a number of Twitter users. “Which McDonald's was this. No matter what that is not acceptable. Fire the employee,” wrote one user. Another commented: “Lock the savage up and sue McDonalds.”

In a 2013 Wall Street Journal report, McDonald’s was criticized for having a high employee turnover. An employee working for the company spoke to WSJ on the condition of anonymity, speaking about the kind of pressure employees at the counter have to go through on a daily basis.

"Let's say I'm in front at the register and the grill's not pushing out food quickly enough. So you have to wait on food, and the customer is getting aggravated at you because you're not giving them the food quick enough, and the grill gets aggravated with the cashier because we're asking where the food is,” the employee said.

McDonald’s is also not unfamiliar to disruptions caused by customers. Earlier this month, a customer threw a smoke grenade into one of the company’s drive-through outlets in DeKalb County, Georgia, prompting the brief closure of the facility.

The customer in question reportedly placed an order at the drive-through, paid for his order, then threw the device inside the facility and sped off in his car. The device in question was a smoke grenade that is often used in paintball games — "a commercial-type smoke grenade that can be purchased online or any fireworks, paintball, airsoft-type facility,” Maj. Brandon Gurley with the Brookhaven Police Department told ABC affiliated WSB-TV.

The grenade did not hurt anyone but did scare a lot of employees working inside the facility.