Last month a Chinese official in charge of internet surveillance gave notice that mobs of web users who turn on individuals and make their lives a misery will not be tolerated. In China it happens often and on a massive scale, earning the phenomenon the title of the "human flesh search engine".
China's internet vigilantes and the 'human flesh search engine'
On Thursday 21 March 2013, the world changed for Yin Feng, a self-described "average guy" who worked as a part-time taxi driver in the western Chinese city of Urumqi.
Just after 14:00 his mobile phone began ringing off the hook. The callers all berated the bewildered Yin, screaming obscenities and accusing him of acting like an animal.
It took a while for Yin to uncover why the strangers phoning him were so upset.
"Finally, some sensible citizens told me a story about me they heard on the radio, or on the internet," he recalls.
Earlier that day, they told him, a driver in Urumqi had rolled down his window to spit on an elderly homeless person lying on the street. Witnesses recorded the first few digits of the spitter's number plate. The information was quickly broadcast by a local radio station.
Thousands then banded together online to track down the perpetrator.
"Driver with the licence plate A36D62, you really humiliate all men," wrote one angry internet user. "Please forward this post and let's see what kind of ugly face he has. Let's extinguish him. Die! Such a disgrace. We don't even know where he's from. Get out of Urumqi."
Hours later, they zeroed in on Yin, whose number plate was a partial match, and posted his mobile number online.
The internet vigilantes were wrong, Yin insists. He tried to defend himself to anyone who would listen, explaining he wasn't guilty of spitting on anyone.
But as soon as Yin hung up with one angry caller, his phone would ring again. And again. And thousands of times again.
"All of my private information was made public. My ID card number, name, phone number, address, even my mother-in-law's phone number was dug out and posted online," Yin remembers. "I even received phone calls blackmailing me, threatening to burn my house down if I didn't pay them 200,000 RMB [$33,000; £20,000]."
Mr Yin was an unwitting target of what has been named China's human flesh search engine.
At its worst, the ghoulishly named "flesh-searching" phenomenon is cyberbullying on an epic scale, sometimes involving hundreds of thousands of anonymous Chinese internet surfers ganging up to uncover the identity of an unsuspecting target. Users band together to uncover a person's identity - sometimes a suspected adulterer, sometimes an animal abuser.
The phenomenon first scored attention in 2006, when many in China began to turn to the internet for the majority of their entertainment. The use of internet forums exploded during that period.
One of the first notorious cases involved the search for a woman who starred in an anonymous video using the high heel of her stiletto to crush a kitten's skull. The woman, who turned out to be a nurse, was suspended from her job when her identity was revealed. She received numerous death threats and considered suicide, Chinese state television reported.
Hundreds of similar cases followed. With 591 million users, China has the world's largest internet population. They're also arguably the most obsessive, picking over the smallest details in photos that capture the public's imagination.
But at the highest levels, it seems the government is taking notice. Last month, Liu Zhengrong, a top Communist official in charge of China's internet surveillance, said the government believed the human flesh search engine was "illegal and immoral". His caution was soon echoed in China's major state media outlets - a signal, Chinese lawyers say, that flesh-searching tactics won't be tolerated in the courts. Legislation might soon follow.
But up until now it has been possible for anyone to find themselves in the crosshairs of China's internet forums.
In 2009, Zhang Zetian was an ordinary high school student. One day, as she was leaving class, a friend snapped a photo of her with a Chinese milk tea drink in her hand, backpack slung over one shoulder. Zhang's photo was then posted on Renren.com, a popular social networking site. Complete strangers then forwarded the photo hundreds of thousands of times, proclaiming the "Milk Tea Girl" to be "adorable!" and "fresh faced!".
"A newspaper reporter called me one day and suddenly I realised that people had noticed me on the internet," Zhang explains. All her personal details were posted online.
Years later, Zhang remains an internet celebrity. Photos of her doe-eyed face are in regular circulation. When she was admitted into Tsinghua, one of China's top universities, her profile rose again.
Sitting in a cafe near her campus, Zhang seems embarrassed by her unlikely rise to celebrity status.
"No matter where I go, people attempt to take secret photos of me," she says. People follow her with cameraphones on campus and sometimes in class. Admirers have even tried to break into her university dormitory.
Those who favour increased policing of the internet to stop flesh-searching cite cases like the Milk Tea Girl as classic examples. When so many strangers focus their attention on a single person, some inevitably go too far.
Sceptics might point to the fact that it's in the government's interest to rein in the practice, since the flesh-searching phenomenon has also targeted members of the Communist Party.
The most famous case of political flesh-searching involves the "watch uncle", a Communist official in China's central Shaanxi province who was spotted smiling at the scene of a deadly traffic accident. Who was this man, many wondered.
They soon discovered he was the province's health and safety chief, a man named Yang Dacai. Some also realised that in every official photograph, Yang was wearing a different designer watch, worth far more than he could afford on his official salary. Days after his smiling face first snagged attention, he found himself without a job.
Since then, watch spotting has become an internet sport and "watch uncles" have been outed all over China. Some officials even attracted attention when their obvious tan lines indicated they had just removed their watches before allowing a photo to be taken.
In small ways, the human flesh search engine is forcing Communist officials to change their behaviour.
By using the internet to police the party, citizens can train their own government to obey the constitution, argues Wu Zuolai, a scholar with the Chinese Academy of Arts in Beijing.
"They get criticised every day, and it will become a regular routine," he says. "Before, leaders locked themselves up in Zhongnanhai [the government leaders' compound], focusing their minds on how to keep the people in sealed boxes without speaking or moving freely. I believe Xi Jinping's era will be more open."
Even if laws appear on the books, Beijing might find it difficult to reign in the public's appetite for scrutinising others.
The internet is notoriously hard to control, even in China, where censors regularly delete blog posts and comments the government deems unacceptable. Some targets of flesh-searching have already taken their cases to court, but it's hard to blame a single perpetrator.
Months later, Yin Feng, the taxi driver, is still shaken by his ordeal. He scans the internet regularly for mentions of his name and he watches other flesh-searching incidents carefully. Attempts to report his experience to the authorities have not had much effect.
Yin hopes the government will enact new laws to give ordinary folk like him power against internet vigilantes.
"Many years have passed since the internet became so powerful," he explains. "If other victims' personal lives are affected like mine was, at least they'll have the law to turn to. If nothing is done, frightening things will happen."
The 'human flesh search engine': Bizarre phenomenon where China’s online community combine in their hundreds of thousands to 'troll' an individual
The power of the internet has become painfully obvious to a number of Chinese citizens who have fallen victims to what officials call the 'human flesh search engine’.
The phenomenon sees hundreds of thousands of online users target an individual in order to track them down, sometimes in order to right an action the mob deem ‘wrong’ or simply because their image has gone viral.
It has been described as a vigilante movement, but due to the mob mentality, innocent people have found their lives ruined by being falsely accused of actions they did not commit.
When an image or an event 'goes viral', meaning that it is being shared in large numbers on online social networks within a short space of time, causes are highlighted, news spread instantly and individuals gain momentary fame or end up ‘named and shamed’ across the globe.
In the closed online community of China, where global communication hubs such as Facebook, Youtube and Twitter are blocked, these ‘viral’ causes tend to stay within the country’s borders.
Despite official censors, who warned of the phenomenon last month, trying their best to monitor content to delete blog posts and comments that disagree with the hardline communist government, the internet moves too fast even for them.
As China has the world's largest internet population with 591 million users – a number which is expected to increase to more than 750million by 2015 - the 'human flesh search engine' strikes swift and hard and can ruin a person's life in an afternoon.
One recent example is a supposedly innocent taxi driver from the western Chinese city of Urumqi found himself accused of humiliating a homeless person in the street.
When a witness spotted a taxi driver spitting on the elderly man on an Urumqi street, he or she noted the license plate and posted it online urging the 'human flesh search engine' to track the man down and make him pay.
The post called for the responsible taxi driver’s details to be spread all over the internet so he could be ‘extinguished’ and forced out of Urumqi.
Within hours, the online mob had located taxi driver Yin Feng. However, Mr Yin claims he is completely innocent.
‘All of my private information was made public. My ID card number, name, phone number, address, even my mother-in-law's phone number was dug out and posted online,’ Yin told the BBC.
‘I even received phone calls blackmailing me, threatening to burn my house down if I didn't pay them 200,000 RMB (£20,000).’
Another example is that of 'Milk Tea Girl' an innocent high school student whose photograph enjoying a beverage went viral.
Zhang Zetian was snapped by a friend in 2009, after which her image spread on Chinese social networking site Renren.com.
'A newspaper reporter called me one day and suddenly I realised that people had noticed me on the internet,' Zhang told BBC, explaining that she remains an online celebrity several years later and that stalkers even tried to break into her university campus dorm.
'No matter where I go, people attempt to take secret photos of me,' she added.
