Chofetz Chaim Daily 14 Taamuz 4:7 One may publicly degrade the actions of someone who has no fear of G-d and clearly doesn’t regret his sins. He may be shamed until he mends bad ways. Do not judge him favorably. 4:8 If one does not heed command of Beis Din (w/o valid excuse), publicly degrade him and record his actions in public records.
Chofetz Chaim Daily 15 Taamuz 4:9 If you see someone has bad middos, you may not badmouth him because he probably doesn’t realize the severity of his actions. Instead, influence him to change. 4:10 You may tell your children or students to stay away from a person with bad middos. However, you must explain why you are telling them.