Children and teenagers are facing an alarming risk of harm online - triggering a major Downing Street crackdown on social media use for under-16s. Prime Minister Keir Starmer issued an explosive ultimatum to Silicon Valley tech giants, warning that if tech barons like Apple and Google refuse to introduce tighter measures on their devices, the government will take action - with the possibility of prison time for officials who don't comply. Under these groundbreaking plans, Britain is set to