But having the doors locked, with security cameras rolling and sign-in procedures in place, is no guarantee of security -- the shooter at Sandy Hook broke the glass and unlocked the door, and was duly recorded while doing so. All of these things are only an illusion of safety, while being a real invasion of privacy at the same time. The shooters will get in if they want to, and the child molesters are already there.
I understand that it might be an illusion, but I would also point out that it gives school personnel some feeling of control. They are scared. As a teacher, I am scared every time I hear about a school shooting. I know it's not statistically rational, but I can't help but play out scenarios in my head.
I also worry because my mother has a severe mental illness and is to have no contact with DS without DH or myself present. But she could easily pick him up at school. We've talked to school personnel, but in reality I know it could happen. And if it did happen, we'd need a record of who had been at the school (sign-in, security footage, etc.).
Many schools use security footage on a fairly regular basis. It's naive to think it's not a useful tool.