I know the laws will vary greatly by jurisdiction. In most cases, the faces of others would need to be blurred and bathrooms/locker rooms would not be recorded. In many places, audio may not be recorded either (2 party consent states). But at least you could see any physical attacks.

Perhaps some of these restrictions are overcome by the camera transmitting to the school system rather than the parents, maybe as part of an IEP requiring a calm/safe environment?