Chu had already served a three-month prison term under an older sedition law, also for wearing and possessing clothes and flags with protest slogans.
The sedition offence was created under British colonial rule, which ended in 1997, and was seldom used until Hong Kong authorities revived it in 2020 in the wake of the protests, charging more than 50 people and four companies.
After the protests were quashed, Beijing imposed a national security law on the city in mid-2020 to quell dissent, and a second, tougher law was enacted locally in March.
The revised law beefed up the offence of sedition to include inciting hatred against China’s communist leadership, and upped its maximum jail sentence from two years to seven.
The new security law also punishes five other categories of crime: treason, insurrection, sabotage, espionage and external interference.
Critics, including Western nations such as the United States, say Article 23 will further erode freedoms and silence dissent in Hong Kong – a finance hub once considered one of the freest territories in China.
Authorities have defended the law as necessary to fulfil a “constitutional responsibility”, comparing it to a “reliable lock to prevent someone from breaking into (our) home”.
As of this month, 303 people have been arrested under the two security laws, with 176 prosecuted and 160 convicted.
