Tech Tent

How the boom in 'non-fungible tokens' helped one artist become a multimillionaire. Mike Winkelmann - also known as Beeple - explains why his art has sold for $69m at auction despite being freely available to download. Also on the programme: A global security breach of Microsoft's email software hits thousands of businesses. We hear from the BBC's cybersecurity specialist Joe Tidy on why so-called 'zero-day' vulnerabilities are so scary. And Onyinye Ough from the organisation Step Up Nigeria tells us how virtual reality is being used to fight corruption in the West African country. Presented by Rory Cellan-Jones, with BBC tech reporter Jane Wakefield. (Picture credit: Christie's/ Getty Images)