Starbucks has apologised to two black men who were arrested while waiting for a friend at one of its branches in Philadelphia.
Cellphone footage shows the pair being placed in handcuffs and led quietly from the store while perplexed onlookers can be heard saying they had done nothing wrong.
An apology issued at the weekend was not enough to prevent demonstrators gathering to highlight Thursday incident and what they said was yet another example of how black people are still treated as second-class citizens in America.
It is an embarrassing episode to a coffee chain that styles itself as a hang-out for people to meet and linger.
Kevin Johnson, Starbucks chief executive, described the video as "hard to watch" and the arrests as a "reprehensible outcome".
"Our store manager never intended for these men to be arrested and this should never have escalated as it did," he said in a statement, adding that he wanted to apologise personally to the two men although he declined to explain why the actions escalated so quickly.
Police said they received a 911 complaint of trespassing and responding officers were told the two men had asked to use the lavatory without making a purchase. Richard Ross, police commissioner, said the men said they were waiting for a friend and refused to leave.
A Starbucks spokesman said the store had a policy of only allowing customers to use the lavatories.
The local district attorney's office said the men were released after Starbucks declined to press charges.
Even so, the arrests caused outrage around the US as details spread across social media.
The Rev Jeffrey Jordan led a crowd of protesters outside the Philadelphia branch in chants of "I am somebody, and I demand equality now."
"It is a shame that (in) the year 2018 we're still putting up with this mess," he said. "This country was built on the backs of black and brown people and now Starbucks is going to treat us like we're second class."
Robert Passikoff, the president of Brand Keys, a New York-based consulting firm that researches brand loyalty, said the fiasco illustrated the dilemma faced by Starbucks as it tried to be both a business and a modern kind of community centre.
"Companies have gone out of their way to establish the kind of emotional bonds and product delivery that they think is going to build engagement and loyalty and, ultimately, profits," he said.
"But today the consumer decides what is right."