It would be a "mockery" of the law to assume there would be no liability for illegal assembly even if there were no violence involved, a Hong Kong District Court judge told seven activists when convicting them for their roles in an unauthorized mass protest in 2019.

District Court Judge Amanda Woodcock ruled that all seven defendants, including media tycoon Jimmy Lai Chee-ying and several former legislators, organized and knowingly participated in the unauthorized procession on Aug 18, 2019, when the city was embroiled in street violence, often derived from peaceful protests. The defendants were arrested in April 2020.

The judge dismissed the defense's position that the defendants should not have been arrested or prosecuted because they were not involved in violence and the march was ultimately peaceful. "That would give the law no teeth and make a mockery of it," she wrote in an 89-page ruling.

The defendants, ignoring the rejection of their application for a public procession, led thousands of people who had taken part in an authorized public meeting at Victoria Park on Hong Kong Island out of the park to march toward Central, prosecutors said.

During the 90-minute march, the defendants carried a giant banner and shouted anti-government slogans through megaphones. One of those holding the banner, former legislator Leung Kwok-hung repeatedly chanted that "no police permission is required" for a procession.

The judge said they encouraged the public to get around the police ban by falsely describing the march as a dispersal from the meeting. It was done to "deliberately flout the law openly", the judge said.

The judge stated in her ruling that the so-called peaceful procession had disrupted public order in Hong Kong, blocking traffic in one of the city's busiest districts. Video footage showed black-clad protesters kicking traffic cones, shining laser lights into government buildings and painting graffiti on walls. At least two passersby were attacked and injured by protesters, according to reports.

Apart from Lai and Leung, the five others found guilty are Democratic Party founder Martin Lee Chu-ming, Labour Party Vice-Chairman Lee Cheuk-yan, barrister Margaret Ng Ngoi-yee, and former legislators Albert Ho Chun-yan and Ho Sau-lan.

Former lawmaker Au Nok-hin pleaded guilty to the same charges regarding the same gathering during a Feb 16 trial, and activist Leung Yiu-chung pleaded guilty to one charge of participating in the illegal assembly.

Sentencing in the cases was set for April 16.