A Hong Kong man on Monday pleaded guilty to sedition for wearing a T-shirt with a protest slogan, becoming the first person convicted under the city's new national security law passed in March.

A Hongkonger has pleaded guilty to sedition over a T-shirt with a protest slogan on it, becoming the first person convicted under the city’s new security legislation. Chu Kai-pong, 27, appeared in front of Chief Magistrate Victor So at West Kowloon Magistrates’ Courts on Monday.

Chu Kai-pong faces up to 10 years in prison under the new security law. Critics have argued that the term sedition has been vaguely defined, and it could be used to curb dissent.