Marketers express unease about Facebook’s handling of hate speech. Plus, how Singapore is introducing wearable dongles to help log and trace people who might have Covid-19. And the simulation company aiming to help redesign cities fit for a post-pandemic world. Presented by Rory Cellan-Jones, with BBC tech reporter Jane Wakefield. Produced by Jat Gill. (Image: A smartphone showing the website of the “StopHateForProfit” campaign, Credit: EPA/ SASCHA STEINBACH).