Zeng Yuxuan, a doctoral student from mainland China found in possession of posters depicting the "Pillar of Shame" sculpture commemorating the Tiananmen massacre, was recently handed a six-month jail term under colonial-era sedition laws.

Zeng's Sept. 12 sentencing came after she was convicted of conspiring with U.S.-based democracy activist Zhou Fengsuo to "commit acts with seditious intent" ahead of the June 4 massacre anniversary, and has sent shockwaves through the growing community of mainland Chinese who have made Hong Kong their home.

Zeng is the first mainland Chinese person to be convicted of sedition under an ongoing crackdown on public dissent that has seen senior journalists, pro-democracy media magnate Jimmy Lai and 47 former lawmakers and democracy activists charged with offenses from "collusion with a foreign power" to "subversion."

Since the 2019 protest movement, police have made more than 1,000 arrests under a draconian national security law, with thousands of protest movement supporters also targeted under colonial-era public order and sedition laws.

Like many defendants keen to avoid months or even years of pretrial detention with no bail, Zeng pleaded guilty to "attempting to commit or preparing to commit one or more acts with seditious intent."

Before her arrest, Zeng had taken part in the "white paper" protests against the stringent restrictions of the zero-COVID policy in November 2022.

But the action that prompted her prosecution by the Hong Kong authorities was her public commemoration of the death of Leung Kin-fai, who committed suicide after non-fatally stabbing a police officer outside the Sogo Department Store on July 1, 2021 in an attack described as "terrorism" by police at the time.

Not the only one

Zeng isn't the only person to be prosecuted for supporting Leung in public.

On Sept. 11, four former University of Hong Kong students pleaded guilty to "incitement to wound with intent" after they publicly praised Leung's action, according to Hong Kong court reporting service The Witness. They had earlier been accused of "glorifying terrorism," but the terrorism-related charges were dropped.

Kinson Cheung, Charles Kwok, Chris Todorovski and Anthony Yung, who are aged between 21 and 22, were arrested in 2021 after they took part in a student union meeting that passed a motion of sympathy for Leung, a move that was denounced in the pro-China press and by then leader Carrie Lam.

Zeng was released on bail following her January arrest, but then rearrested on June 1 after she was found carrying the "Pillar of Shame" posters.

In an interview recorded before her second arrest, Zeng told Radio Free Asia that she was inspired by her first glimpse of the 2019 protests, which came when her law lecturer at a mainland Chinese university used a VPN to circumvent the Great Firewall of government censorship and show the class live footage of protesters occupying Hong Kong's Legislative Council chamber on July 1, 2019.

She later applied to study in Hong Kong, and started keeping up with political developments there, as well as doing some in-depth reading on overseas websites about the 1989 Tiananmen massacre that ended weeks of student-led democracy protests in Beijing and other major cities.

"The outcome was tragic, but there was something quite glorious about the fact that this has now entered into the collective memory of our generation, of several generations -- it's a shared memory," Zeng said.

Zeng arrived in Hong Kong as Peng Lifa was staging his explosive banner protest on Beijing's Sitong Bridge, ahead of the party congress.

Zeng eagerly embraced the "white paper" movement that followed, she said, adding that she felt a "duty" to protest.

"It feels like most people in mainland China don’t actually care about [politics or social justice]," she said. "But I still think it's my duty — it's everyone's duty."

Fearless at her trial

Mainlanders turned out in Hong Kong's Central business district, the working class district of Mong Kok and on the campus of the Chinese University of Hong Kong to hold up blank sheets of A4 in solidarity with "white paper" protesters in mainland Chinese cities.

Yet many had their ID cards photographed by police, leading to fears that their participation could lead to repercussions for loved ones back home.

By New Year's Day 2023, Zeng had been arrested for taking part in a public commemoration of Leung Kin-fai, and the police in China were already in touch with her parents.

"My feeling is that my parents and I are individuals, and independent of each other," Zeng said. "If they target my parents, then the responsibility falls on them, not on my parents."

A fellow Hong Kong-based mainlander who gave only the nickname Sandy for fear of reprisals, said Zeng had seemed fearless at her trial, appearing in a sweatshirt with a Winnie-the-Pooh motif, in an apparent sideswipe at ruling Chinese Communist Party leader Xi Jinping, who is said to resemble the fictional bear.

"A lot of our friends and classmates in mainland China lack the courage to stand up, but they are grateful to those who do," Sandy said. "It's also heartbreaking, because she didn't have to do this."

Another mainlander who once met Zeng as a student in Hong Kong said Zeng's actions had tested the government's vaguely defined "red lines" under the national security crackdown, and that she admires her bravery.

She believes Zeng's sentence was handed down to act as a warning to other mainlanders in Hong Kong who might sympathize with the pro-democracy movement.

"[It's now clear that] the national security law and the [attempted] police assassination attempt are off-limits," the woman, who gave only the nickname Lily for fear of reprisals, said, adding that the space inside the government’s "red lines" appears to be narrowing all the time.

"It's pretty scary whether you're a Hong Konger or a mainlander," Lily said. "I didn't think it would give rise to so many criminal charges."