IN 1967 Mao’s tumultuous Cultural Revolution washed into Hong Kong, stirring anti-colonial riots and bombings. The territory’s British rulers decided to restore order by imposing tougher legislation aimed at preventing crowds from assembling. A new Public Order Ordinance required permission for a public gathering of three or more people. If an illegal assembly resulted in a breach of the peace, each participant could be convicted of rioting.

That sweeping law has been used by the post-colonial government to deter further outbreaks of unrest such as occurred in 2014 when pro-democracy protesters occupied busy streets for weeks, and in 2016 when rioting broke out following officials’ efforts to clear away food stalls selling traditional snacks (the violence was joined by young people who were enraged by the deployment of large numbers of police). On June 11th a well-known activist, Edward Leung, was jailed under the Public Order Ordinance for six years for his role in the mayhem two years ago—the worst disorder on the streets of Hong Kong since the Cultural Revolution. A lesser-known co-defendant received a seven-year term. The two sentences were the longest meted out to any of the more than 100 people who have been prosecuted in connection with the episodes of 2014 and 2016.

Mr Leung, who is 27, enjoys a degree of public sympathy. Soon after the riot, with charges relating to it hanging over him, the then-student of philosophy at the University of Hong Kong stood in a by-election for the Legislative Council, or Legco. He won 15% of the vote—an achievement that alarmed the government in Beijing because it suggested some public approval for the support he had given to the idea of Hong Kong’s independence from China. Later that year he was barred from standing in another Legco election for having expressed such views.

There is no doubt that Mr Leung acted badly: he pleaded guilty to hitting a police officer during the riot, for which he was given a concurrent sentence of one year. But police arrested him within minutes of his assault of the officer, long before the unrest descended into what was far more clearly a riot, involving brick-throwing and lighting of fires. The jury acquitted Mr Leung of incitement. Many local lawyers and politicians have accused the court of sentencing him too harshly.

Among those who have waded into debate about the case is Chris Patten, Hong Kong’s last colonial governor. In a statement, he noted that in the build-up to the territory’s handover in 1997, his administration had revised the Public Order Ordinance “because it was clear that the vague definitions in the legislation are open to abuse.” Many of those changes were revised after China took over to make the law stricter again. “It is disappointing to see that the legislation is now being used politically to place extreme sentences” on democrats and other activists, he said.

Hong Kong’s judiciary remains widely admired for its independence. But the numbers of worriers are growing. “The discretion of prosecutions is ultimately held by a political appointee. There is no insulation from that political process,” says Alvin Cheung of New York University, who has worked as a barrister in Hong Kong. Carrie Lam, Hong Kong’s chief executive, has brushed aside suggestions of political interference in this case. In a territory where anxieties about China’s hidden hand run deep, her words will change few minds.

Article originally appeared in The Economist on 14 June 2018