My kid's public elementary has no unlocked doors after the morning bell. One has to pass through 3 sets of locked doors [[no visibility on outer most door). A nametag with a photo and finger print scan is necessary before passage through the 3rd door. Background checks are mandatory to be classroom aide/chaperone. Shit has gotten intense since I was a kid.

When you think of a vulnerable population with several ways to get in, think about hospitals. Their security protocols are absolutely atrocious.