Protecting the rights of children is one of the biggest priorities of any society that wants to be considered the least bit civilized, and there is a pretty good chance that figuring out who can and can’t touch children is a pretty huge aspect of that. For example, a teacher is usually not going to be allowed to touch a minor even if said minor is one of their students due to the reason that this would be distinctly inappropriate and can lead to encounters that are illegal to say the least.
That said, most people working in residential security are usually allowed to touch minors as long as they are required to do so based on the job that has been handed over to them. This is because of the fact that it is the responsibility of these security guards to find a way to evict people from buildings whenever they are causing a row, and the truth of the situation is that this applies to minors just as much as it does to adults although in the case of minors the first course of action for a security guard would usually involve trying to locate and talk to their parents.
In the event that the parents of a disruptive minor can’t be located, the fact of the matter is that security guards can touch them in order to escort them off the premises. They can’t do this if the minor is complying, but if they are resisting then a security guard would have no other option than to lay their hands on them and drag them out by any means necessary in order to keep things safe and civil.