Dad appears to be a cyber bully. Not real good.
Nope, it is called good parenting. It is called hoping other people with difficult kids can learn from your example. It is called tough love. Dad followed him to school. He was in no danger. It is like my great grandmother. She caught her kids fighting she would put a stop to it and make them go cut some switches. 3. One for her and one for the two fighters. She would make them whip each other or she would whip both. (She had 9 kids and ran an orphanage of 30 more. All the kids she raised turned out extremely successful. One actually become personal friends with Onassis)