YouTube will prohibit videos encouraging racism, discrimination, and violence, following a call by world leaders in Paris last month to curb extremism online and after a report in The Verge detailing the harassment that a journalist had been subject to because of his race and sexual orientation by right-wing commentator Steven Crowder.

"YouTube has always had rules of the road, including a longstanding policy against hate speech," YouTube said in a statement.

"Today, we're taking another step in our hate speech policy by specifically prohibiting videos alleging that a group is superior in order to justify discrimination, segregation or exclusion based on qualities like age, gender, race, caste, religion, sexual orientation or veteran status," it added.

"We will begin enforcing this updated policy today; however, it will take time for our systems to fully ramp up and we'll be gradually expanding coverage over the next several months," YouTube stated.

"We have longstanding advertiser-friendly guidelines that prohibit ads from running on videos that include hateful content and we enforce these rigorously," the statement pointed out.

"Channels that repeatedly brush up against our hate speech policies will be suspended from the YouTube Partner program, meaning they can't run ads on their channel or use other monetization features,” the statement noted without uncovering the names of any groups or channels that may be banned.