(CNN) Even though federal law outlaws discrimination in public restaurants and cafes, there are still incidents in which black customers wait longer to be served, are asked to pay before a meal or sometimes subjected to arrest.
That's what happened most recently at a Starbucks in Philadelphia, where two black men were arrested for trespassing after they had asked to use the bathroom, but were told it was for paying customers only. The video of the arrest went viral, prompting a quick response from the company and CEO Kevin Johnson meeting with the two customers.
The company plans to close its 8,000 company-owned stores in the United States for the afternoon on May 29 to teach employees about racial bias.
Starbucks isn't the first chain to come under fire in racially charged incidents. Other chains have also made headlines in recent months.
In September 2017, a manager and waitress were accused by a customer in Washington state of targeting a group of black men and asking them to pay in advance, according to CNN affiliate KIRO-TV.
Denny's issued a statement saying the company was "deeply disappointed and outraged by the situation" and that it had zero tolerance for discrimination. After an investigation, the company said the employees involved in the incident were no longer employed by the company.
Denny's released a statement to CNN on Tuesday saying it has a zero-tolerance policy when it comes to discrimination of any kind, which includes termination "if warranted."
"There is absolutely no place in our Denny's family for this type of behavior. Since these recent incidents have occurred, Denny's has further elevated its department of Diversity, Inclusion and Multicultural Engagement in order to strengthen all of our practices internally and guest facing," the statement reads.
It wasn't the first time Denny's had such an incident. Between 1993 and 1994, Denny's paid more than $54 million to settle two class-action lawsuits after customers and employees claimed the restaurant discriminated against black people. The New York Times reported that the restaurant was accused of discriminatory practices, such as segregating black people or requiring black customers to prepay for their meal. Thousands of black customers claimed they were refused service or had been forced to wait longer than white customers.
As a result, Denny's not only changed policies with customer service, it also began promoting minority employees and launched a media campaign using minority actors and minority-owned advertising
In February, two women claimed they were racially profiled at an Applebee's in Independence, Missouri, according to CNN affiliate WDAF. Asia Hardy and Alexis Brison were eating dinner when two officers approached them about a "dine-and-dash" incident that took place the day before.
The two women apparently resembled the thieves, WDAF reported. The server's description of the thieves was vague, detailing only skin color and body size. The two women told the officers they hadn't been at the restaurant.
The manager then told the officer the women should pay for their food, leave and not come back, WDAF reported. The women angrily agreed, but they caught the incident on a video that garnered more than 2.2 million views as of February 15.
Applebee's released a statement afterward, saying it "recognized the hurt and pain" caused by the incident.
"We very much regret this occurred and sincerely apologize to our guests and community," the statement reads. "We do not tolerate racism, bigotry or harassment of any nature."
The company also said it reached out to the two women and apologized directly.
A week after the incident, WDAF reported that the restaurant closed and the three employees involved in the incident had been fired.
CNN has reached out to Applebee's to see whether the company had changed any internal policies after the incident, but has not heard back.
An IHOP restaurant in Maine retrained its employees after a March incident in which a waitress asked a group of black teens to prepay for a meal.
Avery Gagne, who is white, witnessed the incident and described the experience at the Auburn location in a Facebook post.
"I heard them order their food, and they were respectful and were not loud or rude etc. We paid and sat there for a few minutes and I heard an employee tell the table that they were going to need to pay upfront and that it was 'a new generation thing," Gagne wrote in his post, which was shared thousands of times.
"I called over the group and asked them if they were seriously being asked to pay upfront and they said yes. So my father, mother and I stood up and began to question why this was happening."
Gagne went on to write that he felt the teens' race was an issue because the waitress immediately brought it up when trying to explain the situation.
"The woman took it upon herself to make this group of teens pay for their meal upfront because she considered them 'high risk.' I don't care who has walked out on your establishment. That does not give you the right to determine who you believe is going to or not," Gagne wrote, adding that neither he, his parents nor any of the other tables around his family paid for their meal upfront.
The restaurant's management took to social media and offered an apology.
"Everyone has been made aware of these inexcusable actions and reminded how we handle matters correctly in the future," read the post on IHOP Auburn's Facebook page. "We have rectified the situation and can guarantee this is not what we condone to go on within our restaurant."
IHOP President Darren Rebelez also apologized, saying in a statement to CNN that the restaurant chain has "zero tolerance for actions that are or allude to discrimination of any type."
Chain spokeswoman Stephanie Peterson told CNN on Friday that the waitress was terminated and the franchisee "used this as an opportunity to review his HR policies and closed the restaurant for an afternoon that same week in order to retrain his entire staff."
Rebelez said the incident isn't reflective of IHOP's commitment to creating "a warm and hospitable dining experience for all guests."