Li said her parents installed a surveillance camera in her bedroom, and would hit her and throw her phone on the floor every time she made mistakes.

She said the violent parenting has left her suffering from trauma.

She planned to find part-time jobs in Beijing to save money and be independent from her parents.

Li said she went to the police because she thought her parents might report her missing and “make a scene”, so she wanted the police to know in advance that she was fine.

Police officer Zhang Chuanbin comforted her and said her parents’ behaviour was the wrong way of expressing their care.

He then contacted the couple and asked them to give their adult child more space and show respect.

Beijing police later reported that Li’s parents had agreed to take down the camera, and she had returned home.

The parents’ behaviour has been widely condemned online.

“So horrible. Having no private space at all despite being 20,” one person wrote on Weibo.

“Children are independent individuals, not parents’ belongings – some Chinese parents should keep this in mind,” said another.

“Even a prison respects people’s privacy more than this,” someone else said.

“She was brave to fight back, and wise to go to the police to avoid trouble,” said a fourth.

This is not the first time a story about Chinese parents installing surveillance cameras to control their children has gone viral.

In June, after her son finished the gaokao university entrance exam, a mother in eastern China’s Jiangsu province thanked a surveillance camera for “accompanying my son for six years”.

There were widespread concerns about privacy infringement, but the mother argued that the camera installed in her son’s bedroom was “all for his better study performance and improved his grades”.

In 2019, a 14-year-old Jiangsu boy called the police saying his father, who wanted to install a surveillance camera in his room, had “violated his privacy”.

The father said the camera was to prevent him from getting addicted to computer games while he and his wife were working.

He then asked his son several questions that many found “suffocating”.

“How much privacy do you deserve? As your father, why shouldn’t I observe you?”

China’s Minor Protection Law only specifies that no organisation or individual should open or read minors’ letters, diaries and online communications except in an emergency, but does not regulate the use of surveillance cameras.

On mainland social media, many parents continue to admit they have installed surveillance cameras in their children’s bedrooms.