Hong Kong student activists Joshua Wong Chi-fung and Alex Chow Yong-kang have been convicted for unlawful assembly and Nathan Law Kwun-chung for incitement over the storming of government headquarters on Sept 26, 2014, the prelude to the illegal "Occupy Central" movement that disrupted normal life in the city for more than 79 days.

After the July 21 court judgment, some British and US media outlets passed unfair and biased remarks against the convictions. Instead of reminding young people not to violate the law, The Wall Street Journal, The New York Times, The Washington Post, The Guardian, The Telegraph and BBC, along with Amnesty International, criticized the conviction, using words and phrases such as "vague", "smacks of political payback" and "a chilling warning to freedom of expression".

But a closer look at Hong Kong's laws would show these accusations are ignoring the rule of law at least. Section 18(1) of the Public Order Ordinance defines "unlawful assembly" thus: "When three or more persons, assembled together, conduct themselves in a disorderly, intimidating, insulting or provocative manner, intended or likely to cause any person reasonably to fear that the persons so assembled will commit a breach of the peace, or will by such conduct provoke other persons to commit a breach of the peace, they are an unlawful assembly."

The actions demonstrated by storming the government headquarters fit the description above. If a group of protesters had disrupted the activities of, say, the White House or 10 Downing Street they would have faced even more serious punishments.

Because of the refusal to follow the laws, and respect the power of the commissioner of police and police force to regulate public meetings, "Occupy Central" caused huge losses and great sufferings to the people of Hong Kong. We saw how Hong Kong's reputation was soiled, its social stability jeopardized and economic activities affected. Judicial conviction therefore is legitimate, which under no circumstances should be seen as "political payback". In the absence of legal consequences, more such illegal movements would have been launched at the cost of Hong Kong's 7 million people.

The prosecution and conviction of lawbreakers have nothing to do with freedom of expression. Justice will be served in accordance with the law. And law enforcement can never be "a chilling warning to freedom of expression".

In fact, the unlawful "Occupy central" or "Umbrella Revolution" sent a chilling warning about the rise of anarchy.

Some Western media outlets have wrongly assumed that those convicted did something worthwhile for the democratic development of Hong Kong. They don't realize that the youths' demands were against Hong Kong's Basic Law; worse they obstructed democratic development.

Article 45 of the Basic Law provides the blueprint for eventually realizing universal suffrage in the Hong Kong Special Administration Region. The National People's Congress Standing Committee, with its interpretations and explanations of the Basic Law, has laid out the framework for the implementation of universal suffrage. And the SAR government has mapped out a plan to elect the next chief executive through universal suffrage. If all of these were respected and followed strictly, we would have been on track to elect the next chief executive through universal suffrage in 2017. Now that goal has been postponed.

The laws that have helped Hong Kong achieve the rule of law include the law of public order, which authorizes the police to prevent, stop or disperse, with force as and when necessary, any unlawful public meeting, procession and gathering. Anyone who disobeys these laws therefore deserves punishment, as they do in the United States and the United Kingdom.

The author is a veteran commentator and professor at the Research Center of Hong Kong and Macao Basic Law, Shenzhen University.