This is the best summary I could come up with:

In March last year a video appeared to show President Volodymyr Zelensky telling the people of Ukraine to lay down their arms and surrender to Russia.

It was a pretty obvious deepfake - a type of fake video that uses artificial intelligence to swap faces or create a digital version of someone.

Central to the system is a technique called Photoplethysmography (PPG), which detects changes in blood flow.

Earlier this year the BBC tested Clearview AI’s facial recognition system, using our own pictures.

Although the power of the tech was impressive, it was also clear that the more pixelated the picture, and the more side-on the the face in the photo was, the harder it was for the programme to successfully identify someone.

This includes a “wild” test - in which the company has put together 140 fake videos - and their real counterparts.

I’m a bot and I’m open source!