China's digital payments have advanced to another level. Shoppers do not need to carry any cards or even their smartphones to make payments at merchant outlets. With face payment technology, they simply need to nod in front of the point-of-sales machines that are equipped with cameras and make their payments.

However, according to researchers interviewed by Agence France-Presse, this technology, which has been widely adopted by the Chinese government, could be misused by the state for their surveillance purposes to monitor and control citizens by tracking their social information.

Despite the data privacy concerns, the technology is being widely adopted by consumers in China. Alipay, the financial arm of the e-commerce company Alibaba, has equipped the technology in devices across 100 cities.

Alipay sees enormous growth potential in the sector and will be spending 3 billion yuan ($420 million) over three years to implement the face payment technology. It recently upgraded its "Smile-to-Pay" system to use a machine that is almost the size of an iPad. Tencent, the makers of WeChat app also launched their facial payment machine last month. More players are looking into tapping the growing industry in China.

Those in favour of the technology say that facial payments reduce time spent standing in queues at a cash counter in the supermarkets and is safer than cards as it does hold the risk of stealing the PIN entered on POS machines.