Half of parents say their children have never spoken to them about harmful online content, polling suggests - with around a quarter unaware of what they are seeing on their smartphones.
The research by YouGov - which surveyed 1,030 parents of children aged eight to 14 - was commissioned by the government, as it consults on whether a social media ban for under-16s should be introduced.
It has introduced a "You Won't Know Until You Ask" campaign aimed at encouraging parents to talk to their children about what they see online, and providing age-appropriate advice. The government said the vast majority of 11-year-olds in the UK now own a smartphone.
The guidance has been developed with expert organisations including the NSPCC, Parent Zone and Internet Matters, and will be available online from today.
In a separate survey by the UK Safer Internet Centre and Nominet to mark Safer Internet Day, more than half of teenagers aged 13 to 17 (60%) say they are worried about AI being used to make inappropriate pictures of them.
More than one in 10 (12%) said they have already seen people their age using AI to create sexual pictures and videos of other people.
It follows the UK's information watchdog launching an investigation into reports that Elon Musk's AI chatbot, Grok, has been used to generate sexual imagery of children.
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The Molly Rose Foundation, a self-harm and suicide prevention charity, has called on tech firms to be regulated like banks to protect children online.
It presented its proposals in parliament last night, at an event addressed by Technology Secretary Liz Kendall.
The charity is calling for new laws which would "end harmful and addictive design, enforce risk-based age ratings and make safety and wellbeing 'the price of admission' for tech firms in the UK".
It is calling for immediate action to "fix and strengthen" the Online Safety Act and tackle the growing risks on social media, gaming sites, messaging apps and "high-risk" AI chatbots.
The charity was founded in memory of Ian Russell's 14-year-old daughter Molly, who took her own life after viewing harmful content on social media.
Mr Russell, who chairs the foundation, said: "We need a bold new reset of online safety laws that can decisively reverse years of quick fixes and put an end to addictive design and aggressive algorithms once and for all."
However, he said an Australian-style policy to ban social media for under-16s - which is being consulted on by the government - would only give families a "false sense of safety".
"The government should have the courage to act on the evidence and stand up for children by delivering the tough and wide-reaching regulation that they promised in opposition but are yet to deliver," he added.
(c) Sky News 2026: Parents admit they have no idea what their children look at on their smartphones
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