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.

A second-hand car website has seen its value rocket to more than $1bn (£750m), putting it into unicorn status.

India's Cars24 has seen a big rise in business during the pandemic as people look to alternatives to public transport such as pre-owned cars.

India's popular but unreliable rail networks were shut off completely when the country went into lock-down.

A unicorn refers to a privately-owned start-up firm that is now valued at more than $1bn.

Other start-ups that have gone on to become unicorns, and household names, include Uber and Airbnb.

The phones began ringing off the hook at Piero Tintori's company Better Examinations back in April.

His tech business allows tens of thousands of students to remotely sit exams at the same time, with each needing just a laptop, a webcam and an internet connection.

The firm's software uses machine learning (ML), an advanced form of artificial intelligence, to detect patterns in user behaviour that could indicate attempts to cheat. Its technology can also automatically mark multiple-choice answers and mathematics exams.

In addition, it checks each exam-sitter's identity using the webcam, to ensure that no-one else is sitting the test for them. The Better Examinations program also temporarily restricts access to the internet, or certain websites and applications on each person's computer.

"We had 60 organisations from all over the world contact us out of the blue, who wanted to run exams online in May and June," says Mr Tintori. "Everything from universities, to professional organisations, to schools."