Children can already be prevented from sharing some explicit images, but the UK wants tech firms to go furthermartin-dm/Getty Images

Tech firms have three months to put in place measures that stop children in the UK from being able to create and share explicit images of themselves on devices – or face regulation to enforce this.

“I am calling on tech companies operating in this country to introduce vice controls that prevent children from sending and receiving sexually explicit images,” said UK Prime Minister Keir Starmer in a speech on 8 June. “This is not an impossible challenge. If they choose not, then we will act, and we will change the law.”

Apple and Google, creators of the world’s leading smartphone operating systems, have already partially implemented such controls. Apple’s iOS has a feature called Sensitive Content Warning, which detects when a device sends or receives an image or a video that contains nudity through its first-party Messaging or AirDrop systems, and then blurs it. The system is turned on by default for child accounts on Apple devices, but doesn’t check images for nudity when they are taken – instead, it does so when they are sent or received. It works by running images through on-device machine-learning models to assess whether an image contains nudity.