Sam Smith's tweets about racial abuse in the street in London
Sam Smith has taken on everyday racism via a series of tweets after his friend was apparently racially abused.
The singer told his millions of followers that he "never ever ever ever thought that would happen" in London.
He added that he felt he had "to shine some sort of light on it".
There's no more detail about what exactly happened and where - but some followers are mocking the star for only just noticing racism is still a problem.
But Show Racism the Red Card, an anti-racism charity, think it's a good thing Sam's raising awareness of the issue.
"Sam Smith's tweets today show the impact that racist abuse can have," Gavin Sutherland, campaign coordinator, told Newsbeat.
"To witness it or experience it is shocking and it's good that he is highlighting this experience to his many followers.
"It's also true that racist incidents occur every day and it needs to be educated against to prevent it.
"I am sure that he is aware of that and was reacting in shock to a personal experience; it seems silly to criticise someone for that."
Sam's tweets about the incident
Newsbeat has contacted London's Metropolitan Police about the incident. They are "aware" of Sam's tweets but have no further comment.