Should our photos and messages always be private?

Apple is to scan users' iPhones for images of child abuse. Privacy advocates are dismayed. They say it's a slippery slope to monitoring a wider range of content. Andy Burrows from the UK's NSPCC tells us why Apple's move is an important step in protecting children online, while India McKinney from the Electronic Frontier Foundation explains why privacy activists like her are so worried. Namrata Maheshwari from the campaign group Access Now describes the battle between WhatsApp and the Indian governmentment over access to encrypted messages - an example of the wider battle between governments and tech firms over access to data. And Andersen Cheng, CEO of the tech company Post-Quantum, tells us about the time he invented a messaging app so secure it became the app of choice for a terrorist organisation.

(Photo: Messaging apps on an iPhone screen. Credit: Getty Images)