The Australian PM calls for a social media ban for under-16, emphasizing its role in reducing online harm and safeguarding young users

Social media giants on Friday hit out at a landmark Australian law banning them from signing up under-16s, describing it as a rush job littered with "many unanswered questions". The U.N. children's charity UNICEF Australia joined the fray, warning that it was no "silver bullet" and could push kids into…