On a busy Monday afternoon in late October, a line of people in reflective vests stood on Happiness Avenue, in downtown Beijing.
Moving slowly and carefully along the pavement, some crouched, others tilted their heads towards the ground, as curious onlookers snapped photos.
It was a performance staged by the artist Deng Yufeng, who was trying to demonstrate how difficult it was to dodge CCTV cameras in the Chinese capital.
As governments and companies around the world boost their investments in security networks, hundreds of millions more surveillance cameras are expected to be installed in 2021 - and most of them will be in China, according to industry analysts IHS Markit.
