Facial recognition is one of the fastest-evolving technologies in the field of artificial intelligence. It has major implications in terms of security and counter-terrorism, but also e-commerce and industry. In China, the technology is increasingly becoming part of people's daily lives and there are already 170 million surveillance cameras across the country. The economic stakes are huge, but so are the privacy issues and ethical questions raised. Our correspondent reports.
A programme prepared by Patrick Lovett and Christopher Davis