British Prime Minister Keir Starmer strode onto a stage at London Tech Week and handed Apple, Google and friends a three-month ultimatum with all the menace of a substitute teacher confiscating phones at the door. Build us controls that stop children from taking, sharing, or viewing nude images, switch them on by default across every phone and tablet already humming away in the nation’s pockets, and look sharp about it.

“This government will not stand by while children are put at risk online,” he announced, before adding the line every tech executive in the room heard as a polite threat.

“Today I am calling on the tech companies to introduce device-level controls to prevent children from taking, sharing or viewing nude images. And if they don’t act, we will.”

Stirring stuff. Nobody wants children harmed, and saying so out loud is the cheapest applause line in British politics.

The trouble is the two innocent-looking words tucked into the speech like a wasp in a picnic basket, the words “device-level.”

Here is what “device-level” means once you peel off the cuddly branding. To catch one naughty photo on your phone, something has to inspect every photo on your phone. All of them.

It is software that leans over your shoulder the instant you raise your camera, squints at whatever you are making, and decides whether you may keep it or it gets reported to authorities.

Engineers named this trick years ago, client-side scanning, and even Apple, a company that would happily sell you the air inside its packaging, built a version of it in 2021 and then sprinted away from the idea the moment people worked out what it did to private messaging.

The worst part is what it does to encryption. End-to-end encryption is meant to mean nobody in the middle can read your stuff, not the app, not your internet provider, not a bored government with a search warrant fetish.

Client-side scanning waltzes around all of that by reading your photo on your own device first, before the encryption clicks shut. The lock on the front door stays bolted. There is just a man with a clipboard standing in your hallway, jotting notes before you turn the key. The math survives. The privacy, meanwhile, is dead.

Step back and admire how casually people are treating this. A government politely asking every phone maker to install a tiny invigilator inside the camera lens, marking your snapshots as they form, would have been thrown out of a Black Mirror writers’ room a decade ago for being too on the nose.

Picture a painter glancing up mid-brushstroke to find a man from the Home Office at the easel, tutting and scraping off the bits he disapproves of. That is the energy on offer, rolled out across roughly every handset in Britain and wired, in theory, to phone home about what it spots.

Ah, but adults will be fine, we are assured. Officials promise the controls will not bother devices “owned and used by adults who verify their age.”

The opt-out for surveillance is, gloriously, more surveillance. To switch off a child-lock on a phone you bought with your own money and legally own, you must first march up to the state and prove who you are.

Self-described panopticon enthusiast, Home Secretary Shabana Mahmood, is having precisely none of this doom-mongering. “I make no apologies for doing the right thing to protect children from paedophiles. This is about stopping the coercion and sextortion of children, not surveilling or policing people’s phones,” she insists, with breezy confidence.

The tech already exists, she reckons, and the companies merely need to flip a switch as through the death of civil liberties were a bedside lamp.

Her headline reassurance arrives wrapped in magnificent certainty. “There is no reporting, no data collection, no monitoring, and no images leaving the device. All adults will be able to switch off the protections if they are over 18.”

Nothing leaves the device. None of it. Pinky promise, says the secretary from the government who asked Apple to secretly install backdoors to iCloud.

The EU spent two years building almost exactly this contraption, christened it “Chat Control,” and then watched it die a richly deserved death.

The European Parliament finally pulled the plug this March, rejecting blanket scanning of private messages by a single vote. For now.

Even Germany, a country with a long and unhappy memory of governments steaming open the mail, refused outright on constitutional grounds, and its justice minister compared mandatory message scanning to “opening all letters as a precautionary measure.”

Signal announced it would simply pack up and leave the continent rather than gut its own encryption.

As we previously reported, working from Germany’s own federal police figures, found that 48 percent of the chats flagged by automated scanning turned out to be completely innocent. Family holiday photos. Medical pictures sent to a doctor. All hoovered up and forwarded to police as suspected child abuse because a robot got the jitters.

Here is the part that should make your eye twitch. A parent who wants a child-lock on their kid’s phone can switch one on today. For free. They just have to turn it on. It requires parenting, not state control.

If you are tempted to extend the government some benefit of the doubt, cast your mind back over the past year.

This same Home Office served Apple with a secret order, a Technical Capability Notice, demanding a backdoor into end-to-end encrypted iCloud backups, first for every human on the planet and later, after Washington threw a tantrum, for British users alone. Secret being the operative word, since the law gagged Apple from so much as admitting the order existed.

Apple’s answer was to rip its strongest encryption out of the UK entirely rather than build the thing, sniffing that it has “never built a backdoor or master key to any of our products or services,” and the fight is still grinding through the courts. That is the track record of this government, one that asks one company, in the dark, to dismantle encryption for an entire nation is not a government you hand a camera-side scanner and trust to use it gently.

So spare a thought for what this little inspector gets up to once it tires of policing teenage selfies. A system that can read every image on every phone, sold to you today as a babysitter for the under-18s, is exactly the system a future minister could repoint at protest photos, leaked documents, unflattering memes, or whatever sets off the moral panic of the week.

Nobody has explained how you age-verify tens of millions of adults without assembling the enormous identity database ministers swear blind they are not building. Nobody has explained how “nothing leaves the device” survives in the same room as a snooping model that someone in an office has to keep trained, updated and told what to flag.