The U.K. has, as widely expected, announced plans to ban social media for under-16s - but the controversy won't be going away any time soon.

The decision follows a similar move by Australia, which requires platforms to make sure that under-16s aren't using their services, while Spain is planning a similar ban. France and Norway are looking to do the same for under-15s.

On the same model as Australia, by this time next year, the U.K. ban will affect user-to-user platforms and algorithms, meaning it will apply to platforms such as Snapchat, TikTok, YouTube, Instagram, Facebook and X, but not messaging services like WhatsApp and Signal.

Functions such as livestreaming will also be blocked, as will strangers communicating with under-16s, with the restrictions applying to a wider range of online services than in other countries, including on gaming sites.

And ‘romantic companion’ chatbots – designed to simulate sexual relationships or roleplay with users – will have to enforce a minimum age of 18, as will similar intimate functionalities on AI chatbots more widely.

"This is a line in the sand. Tech giants had their chance and failed, but we’re stepping in to protect children, back parents and set a new normal for future generations," said prime minister Keir Starmer.

The government said this was a "first step", and that further measures may be added in future.

As to how all this will be put into practice, the government is keen to claim that it won't have similar problems to Australia, where children have routinely been able to bypass the ban, by introducing more highly effective age assurance (HEAA) measures. Regulator Ofcom will carry out a rapid study on what is effective age assurance for verifying whether someone is over 16.

However, the decision is highly unlikely to end the controversy, with Julian Hayes, surveillance and data protection lawyer at BCL Solicitors, saying it's full of contradictions and problems.

"Clear tensions exist between protecting teens from social media dangers when, simultaneously, we say they are old enough to join the military and vote," he pointed out. "Without prior exposure to the online world, how will young people build the digital resilience to cope when the guardrails are suddenly removed on their 16th or 18th birthdays?"

It’s also rather performative, said Professor David Ellis, chair of behavioral science at the University of Bath.

"This ban is based on worry, not evidence. The evidence base as it stands suggests social media has a minuscule effect, if any, on teenagers - particularly once you account for the other factors we know shape childhood development," he said. "It's also unlikely to be straightforward to enforce, given what we've seen elsewhere, and it risks pushing teenagers towards less regulated parts of the internet. Worse, it lets social media companies off the hook: they can divert resources away from making platforms safer, despite the fact that many young people will simply remain on them."

Others have criticized the proposals for failing to tackle addictive design features such as autoplay and infinite scroll, and failing to compel social media companies to be transparent about the algorithms that determine which content users see.

"The answer is not only tougher rules such as this ban, but better enforcement. Platforms need privacy-first age verification that proves a user is old enough without collecting more personal data than necessary," said Alex Laurie, GTM CTO at Ping Identity.

"The technology exists; now we have clarity from policymakers, it’s time for urgency from tech companies.”