In loco parentis. Read a book.
The doctrine of "Loco Parentis"Britannica.com:
[teachers] [...]
The doctrine of in loco parentisWhen minor children are entrusted by parents to a school, the parents delegate to the school certain responsibilities for their children, and the school has certain liabilities. In effect, the school and the teachers take some of the responsibility and some of the authority of the parents. The exact extent and nature of this responsibility and power vary from one society to another and from one school system to another. This is spelled out to some extent in the law, but much of it is determined by local custom and practice.
There is, of course, a relation between the age of the child on the one hand and the teacher's responsibility and liability for it on the other. The young child must obey the teacher, and the teacher may use the methods expected and tolerated in the community to control the child's behaviour. Furthermore, the child's physical safety is entrusted to the school and to the teacher, who thus become legally liable for the child's safety, insofar as negligence can be proved against them.
Now we know your personal standard of "local custom and practice." Other than you only the late great pervert robertpaulsen considers the actions that took place in this school as examples of "methods expected and tolerated in the community to control the child's behaviour." You have the "facts" of an untried case on your side. The ones you pick and choose. What you don't have is any sense of decency or propriety that anyone else on this board agrees with. That is a fact. You are viewed here as a repugnant, immoral zealot for authoritarian control of the population. That is also a fact. You have your "facts" and we have ours. Good day to you, slug.