Mobbing
によるポスト Frank (confidential) に ドイツ フォーラム
Bullying (or Mobbing, as it's more commonly called) is of course illegal in Germany.
It does happen, though, from time to time. And if it does, enforcing the law or even proving what actually happened is not always easy.
But if your son is so paranoid about mobbing that he bases his choice of residence on the relevant ant-mobbing laws there, I think he should stay on comfortable home ground instead!