SINGAPORE — Six months after sharing a photograph on Chinese social media celebrating her graduate school admission with her bedridden grandfather, Zheng Linghua died.

The 23-year-old had shared the image on the platform Xiaohongshu - sporting pink hair and visibly excited, she announced to the world that she had earned a spot to study music at East China Normal University.

But her joy was short-lived.

Within days, she had become a target of bullying online. Her photograph was shared with false, and often insulting, captions. She then became the target of relentless taunting, with some calling her a "nightclub girl" and an "evil spirit".

It's unclear how Zheng died but last month a friend of hers broke the news on Xiaohongshu: "Because of bullying online and in school, Zheng Linghua's life ended on January 23, 2023".

While so-called cyber bullying happens everywhere, China's collectivist culture and the lack of pressure on social media companies to stamp out abuse lend the phenomenon a particular momentum. A poll of more than 2,000 social media users in China found that about four in 10 respondents have experienced some form of online abuse. It also found that 16% of the victims had suicidal thoughts. Almost half experienced anxiety, 42% insomnia, and 32% depression.

Zheng initially had plans to confront her online abusers with legal action — one of her Weibo posts last September was on "how to sue people who madly attack you from behind the screens?" But she was later diagnosed with and medicated for depression, which she revealed on her social media, sharing details about how she had been battling sleeping and eating disorders. In November, she shared pictures of herself in a hospital ward with the caption: "actively fighting depression".

Her death is just one in a string of deaths that have been linked to online bullying in China.

In January 2022, Liu Xuezhou from the city Xingtai killed himself after a reunion with his birth parents turned sour. As their row played out online, some people accused him of being selfish. The 17-year-old, who was orphaned at the age of four, left behind a note detailing his past experiences with bullying and depression.

History teacher Liu Hanbo from central Henan province died in November that same year after trolls gate-crashed her online classes repeatedly. They hurled insults, played loud music, and spammed the group conversation. Authorities ruled out foul play in Liu's death but said they would investigate if she had been bullied online.

Last month, online influencer Sun Fanbao killed himself - his wife said the 38-year-old was repeatedly insulted by one of his followers and became depressed in the months before he died. Sun shot to fame in 2021 after documenting his 4,000-kilometer trip from Shandong to Tibet on a tractor.

In collectivist cultures such as China, those perceived as going against the norm tend to be severely punished, experts say. What makes it worse, they add, is a pervasive culture of shame.

"A strong sense of collectivism in China can mean that cyberbullying, when perpetrated as a symbolic act of violence or aggression towards another in a public setting, may lead to drastic measures, such as suicide, to escape that sense of humiliation," says K Cohen Tan, a vice-provost at University of Nottingham Ningbo China.

Reading through the posts and comments, it's hard to know what drew the trolls to Zheng. It could well have been her unconventional pink hair, which appears to have bothered some of her online attackers.

Dr Tan says online bullies typically "stigmatize individuals for their personal actions or choices" and that is "later compounded by herd instinct". The combined effect, he says, "leaves victims feeling helpless".

While online vitriol is not always politically charged, the Chinese government "tolerates a specific type of cyberbullying" by right-wing nationalists, says Fang Kecheng, a journalism professor at The Chinese University of Hong Kong.

The subjects of such attacks have largely been people who were seen as tainting China's image in the eyes of the world.

Michael Berry, who translated Wuhan Diary - a journal published by writer Fang Fang during her time under Covid lockdown in Wuhan - has been a target of such trolling.

"Some threatened to kill me and my family if we ever came back to China," Dr Berry said in an interview with WhyNot, a US-based magazine. "Many of these messages contained serious threats and spoke of a deep hatred. Some users were sending me threats like this on a daily basis."

Fang Fang too faced a backlash online, with some accusing her of giving foreigners "a giant sword" to attack China.

The New Yorker magazine's staff writer Fan Jiayang and her mother were also attacked by Chinese nationalists online, calling them traitors, after she publicized her mother's struggle with ALS, a motor neurone disease, in the midst of the pandemic.

Many believe social media platforms in China should be held to greater account, as platforms are elsewhere in the world.

"It has been very difficult for victims to seek legal protection and redress," assistant professor Fang says. "There has been very few cases in which the offenders and the platforms are punished."

This is partly because bullying online is not prioritised as a problem by social media companies or Beijing, which instead runs an extensive censorship machine to stifle dissent or any form of a political conversation.

Social media platforms in China reportedly abide by a growing list of censored search terms - in recent times, these have included words like "Urumqi" and "Shanghai", cities where anti-Covid protests have taken place.

"China has robust technological tools for monitoring online content. More of those resources should be redirected toward curbing cyberbullying. [The government] should not condone the culture of fostering online 'hate campaigns'," says Jonathan Sullivan, a China specialist and political scientist at the University of Nottingham.

Some are also calling for more public education on online safety.

Schools should implement emotional and social learning programmes that teach students how to resolve disagreements and make responsible decisions, said Janis Whitlock, who directs the Cornell Research Program on Self-Injury and Recovery at Cornell University.

More fundamentally, mental healthcare should be strengthened in China, Dr Sullivan says.

Experts say nearly three years of strict and abrupt Covid lockdowns may also have increased time spent online, leading to more instances of bullying.

"What else are you going to do if you are locked down for months on end? This in turn, has also led to an exponential increase in online violence and cyberbullying. Part of this comes from the fact that people were out of work, frustrated, and angry," Dr Berry says.

"People felt like they needed an outlet to vent. And in many cases, they turn to 'keyboard justice', unleashing attacks against celebrities and other public figures," he adds.

In one of her last Weibo posts in October, Zheng reflected on so-called "black swan events" that she experienced last year. Among other things, she listed online abuse, internet violence, depression, and graduate school applications.

"Yes, my dramatic life is fast-paced and fluctuates a lot. But these things have helped me muster courage to go through life's ups and downs, and not lose my way... Next year will definitely be better," she wrote.

Zheng went silent on social media soon after, but up until last month, friends and followers have been leaving comments on her Weibo account, many expressing regret and shock over her death.

"I can't believe this at all. You were such a wonderful human being," one of them wrote.

Another said: "My sadness is unspeakable. I am so disappointed with this world." — BBC