Lenore Skenazy documents the advent of "stranger danger" pretty exhaustively in Free Range Kids. What started out as the ABC Sunday Night Movie about White Women in Peril transmogrified into White Child in Peril as soon as Fox gave John Walsh a place to imply children were being abducted on every street corner and then left him there for 25 years. As soon as kids started shooting each other you couldn't save the kids from the kids.
They precipitated vast changes in the freedoms we were allowed during school hours, which basically changed from a minimum to a medium security prison overnight.
Graduated in '92, should have been '93. We had gun racks. .22s were fired in the hallway a couple times. We went out to lunch wherever we wanted and if you were going to ditch, you were going to get in your car and leave. They gave us ID cards and we, the senior class, threw them vertically so they stuck into the ceiling tiles in front of the office. Then they tried to make us make up for the four weeks of afternoons we lost because of bomb threats and we all walked out.
Next year's senior class was told that campus was closed and that they had to show picture ID to get into the parking lot. And because they were pussies, there were metal detectors by '97.
What freaked me out when I went back to community college in 2017 was all the drilling and signage around "your classmate is going to come to school with an AR-15 some day, here's how you be ready." It's as if the administrations collectively decided that the best way to deal with locking the chicken coop was to teach the chickens to hide at a moment's notice.
The 30-year infantilization of American children is one of the greatest, most terrible trends nobody talks about. The fact that "adulting" is a thing tells you more than you need to know about the harm generated by 'boomer "protective custody."