Schools in some of Canada’s largest cities have joined the legal fight against social media companies with lawsuits claiming Meta Platforms Inc.’s Facebook and others are harming children’s mental health and learning. School districts in Toronto, Ottawa and Peel Region filed separate legal actions Wednesday seeking a total of about C$4.5 billion ($3.3 billion) in damages. The suits against Meta, TikTok owner ByteDance Ltd. and Snapchat parent Snap Inc. claim the companies deliberately targeting ...