Mesira to preserve and protect a just society

R' Breitowitz has an excellent shiur concerning the natue of mesira and its relevance when a just government is involved (Aruch HaShulchan) or the laws are more severe than the Torah (Rav Moshe Feinstein) and its connection to dina demalchusa dina (Rav Wosner) and the need for laws for the well being of society.