CEOs from some of the biggest social platforms will appear before Congress on Wednesday to defend their companies against mounting criticism that they have done too little to protect kids and teens online. The hearing, set to begin at 10 a.m. ET, is the latest in a long string of congressional tech hearings stretching back for years, with little in the way of new regulation or policy change to show for the efforts. The Senate Judiciary Committee will host the latest hearing, which is notable mostly for dragging five chief executives across the country to face a barrage of questions...