China on Sunday introduced a new rule that requires people to have their faces scanned when registering mobile phone services, as experts and even state media raised concerns there were not sufficient measures in place to safeguard people's privacy.
Before the introduction of the new requirement, which was announced in September by the Ministry of Industry and Information Technology, people registering for mobile phone services had to provide only a copy of their identity card.
The ministry said the new measure would help to stem the resale of sim cards and protect people from unknowingly registering for phone services in the event of their identities being stolen.
Many online services and social media in China are tied to mobile phone numbers to ensure users are traceable.
Some people said online that telecom operators had begun insisting on face scans before the official launch.
Some said they hoped the new measures would help reduce telecom fraud and phone scams, while others said it was just another example of the government increasing its surveillance of its citizens.
On Thursday, Beijing joined about a dozen cities across China in using facial recognition systems on its underground rail network. The technology has also been used for many commercial applications and by public security departments.
Some experts said they were concerned that the technology was being implemented without the proper safeguards in place.
Lao Dongyan, a law professor at Tsinghua University, said China did not have an overarching law regulating facial recognition technologies.
"The protection [of personal data] in the criminal law is not enough," she said at a symposium on facial recognition and privacy protection in Beijing last week.
"For most of the time, we don't know our data is being collected and the storage and use of data doesn't follow legal requirements.
"Obtaining people's personal data needs their consent, according to China's laws and regulations, but in reality, facial recognition technologies are widely used while the public rarely knows about them."
Last month, a law professor in east China's Zhejiang province who bought an annual pass for a wildlife park sued the park authority for breach of contract, after it replaced its fingerprint-based entry system with one that uses facial recognition.
A report by state broadcaster CCTV on Saturday said many apps in China collected people's facial data without a user agreement.
In one case, more than 5,000 pieces of facial data were sold online for only 10 yuan (US$1.40) each, prompting Communist Party mouthpiece People's Daily to issue a commentary saying people should have the right to say no when asked for face scans.
"The misuse of legally collected data may be a bigger threat, but we don't have regulations on the misuse of data in the criminal law," Lao said.
But even if there were legislation in place to protect people's facial data, some legal experts said it still would not prevent the risk of personal information finding its way into the government's hands.
"Once this technology is used on a large scale, we have nowhere to hide," said Beijing-based lawyer Wang Xinrui. "The risk of facial recognition technologies is high and far-reaching."
This article was first published in South China Morning Post.