Former student activist Tony Chung was on Tuesday jailed for three years and seven months for secession and money laundering.
He had earlier pleaded guilty to the charges under the national security law.
The District Court heard how Chung, 20, used his role at the now-disbanded Studentlocalism group to publish seditious messages on social media and also held activities and protests last year with secessionist intent.
His defence lawyer, Senior Counsel Edwin Choy, called for a lenient sentence, urging the court to take into account Chung's guilty plea, his young age, and that he had been affected by the social atmosphere in Hong Kong.
Passing sentence, judge Stanley Chan said although the defendant didn’t have a specific secession plan, his goal was clear enough, pointing out that secession doesn’t necessarily involve the use of force.
The judge went on to say that had Chung not been arrested by the police in October last year, he could have continued with his criminal acts.
Chan said the sentence had to serve as a warning to others of the consequences of such behaviour.