Product designer Lui Sheuk-hang, 31, was the first protester convicted of rioting outside the university on November 18, 2019, when more than 100 people gathered to support protesters caught inside the campus by a police siege.
District judge Frankie Yiu Fun-che said the three years and nine months term reflected the seriousness of the offense when people blocked roads during the three-hour protest.
He said some people used cable ties to build barricades and others threw marbles on roads.
Although there was no evidence to show Lui had engaged in violent activities, the court should consider the seriousness of the whole rioting incident instead of his own behavior, Yiu said.
But Yiu said Lui did not lead the rioting and there were no serious injuries in the incident.
The 26 marbles and 100 cable ties found on Lui, who was dressed in protective gear, upon his arrest after falling on Wuhu Street and bricks at the scene could be used to obstruct officers from advancing, he said, jailing Lui for three months for possessing instruments fit for unlawful purposes. But the terms for the two charges would be served concurrently.
Upon hearing the sentence, some people in the public gallery waved at Lui and shouted "we will wait for you" and "hang in there."
Lui pleaded not guilty, saying the marbles were playthings for his cat and the cable ties were used to fasten wire nets across windows to protect it.
Lui said he only returned to campus to witness the end of the siege, but his claim was rejected.
In mitigation, the defense said family members and many friends all praised him as a "good teenager, brother and colleagues" with great knowledge, adding Lui is a filial and family-oriented person.
"In a word, the whole world has praised him," the defense said.
Lui is a first-time offender who will continue to study while serving his jail term.
Elon Musk confirmed that he owns Dogecoin, Bitcoin, and Ethereum during a session at the B Word conference on Thursday.