A man was taken into custody Monday for molesting an underage girl in the eastern Chinese city of Nanjing, though it’s not the person net users were quick to “identify” when photos of the incident began circulating online.

In response to reports Saturday that a young man who appeared to be in his early 20s was seen fondling the chest of a girl roughly half his age at Nanjing South Railway Station, local police announced that they had launched an investigation. Unfortunately, this message came a little too late, as angry Chinese net users had already taken matters into their own hands.

As posts about the incident went viral on microblog platform Weibo, vigilante researchers misidentified a young man who resembled the person in the photos as the alleged molester. Recent university graduate Li Bingxin soon began receiving messages from friends, colleagues, family members, and even classmates he hadn’t spoken to in years, all asking the same question.

“More than anything, it’s been a hassle to explain myself,” Li told The Paper, Sixth Tone’s sister publication. “If my company hadn’t helped me to clarify [where I was] using its public WeChat account, it would have been worse,” the 22-year-old added, referring to a message his company published on China’s most popular chat app.

In fact, Li was at dinner with three of his colleagues in Hangzhou, capital of Zhejiang province when the molester in Nanjing — a three-hour drive away — abused his young victim.

The Weibo user who first voiced suspicions that Li might be the person in the photo has since deleted his initial post. His subsequent posts have provided updates on the police investigation.

According to a statement issued by Weibo on Monday, any user who reposts photos of the abuser, shares false information, or “causes a bad influence” will be banned from Weibo for 30 days. The local public security bureau also reminded netizens not to spread rumors and to respect the privacy of others.

The actual person who had been photographed at the Nanjing train station turned out to be the girl’s adoptive brother.

The Chinese public has become more attuned to issues of child sexual abuse in recent years because of a spate of shocking, high-profile cases.

The same day that police detained the Nanjing railway suspect, another case of child molestation was reported in the southwestern city of Chongqing, where a middle-aged man was seen putting his hands down the pants of a young girl in a hospital lobby. Police investigated the matter and arrested the girl’s uncle, who later confessed.

In China, the online naming and shaming of otherwise unknown people who say or do things that others find objectionable is so common that there is even a colorful term for it: the “human flesh search engine.” And despite government efforts to ban this approach to holding people accountable, it has been applied to a wide range of subjects, from vandalizing ancient Egyptian rock carvings to abusing animals.

But the “human flesh search engine” is a flawed mechanism of justice. In 2014, a woman in southern China’s Guangdong province uploaded a video online of a student whom she accused of stealing from her clothing shop. The girl netizens identified from the video was so overwhelmed by the cyberbullying that followed that she eventually killed herself. Whether she had stolen any clothes was never confirmed.

The U.S., too, saw a “human flesh search engine” case over the weekend in the wake of a white supremacist rally in Charlottesville, Virginia. As photos of mostly white men marching with Tiki torches began circulating online, social media users began revealing their identities. One man in the photos was misidentified as Kyle P. Quinn, a university professor. After receiving death threats, he and his wife left their home to stay with friends out of concern for their safety.

“I think it’s dangerous just to go out accusing people without any kind of confirmation of who they are,” Quinn told The New York Times on Monday. “It can ruin people’s lives.”

Contributions: Yin Yijun and David Paulk; editor: David Paulk.

(Header image: iStock/VCG)