It's not about what you hear about, it is about what can actually happen. You or I don't know what has happened. So much does happen that never gets told. So yes they all need to be checked out. No they don't have to hold something over someones head forever. Just use common sense. You said the teachers are most of the problem and that they have been checked.... Why haven't they all been drug tested? That's where they are failing our children.