Are you sure you aren't thinking about high schools? My high school--which was always a bit closed as no one ever particularly wanted random people showing up a

Are you sure you aren't thinking about high schools? My high school--which was always a bit closed as no one ever particularly wanted random people showing up and interacting with kids--went into a ridiculous lockdown after Columbine and never recovered with access restricted to a single entrance with a stationed guard, limited access to hallways... and it has only gotten worse over the years. The college I'm at, however, has always been set up where, during the day, you can just wander into any building and go into any room and no one really cares. When I was a student I sometimes would just go explore random areas of campus to try to see what people were working on, and most of the doors everywhere are just open (not unlocked... open). If you want to crash a class, the question was really only whether the room was small enough that the professor would notice and simultaneously care to call you out ;P. Other than COVID--which has led to weird incentive systems that might not go away soon :(--the only time I've seen people care much about having things locked or with limited access has been due to issues of theft, not due to shootings (which HAVE happened in my area--my college even got nationally famous due to one in 2014-ish--but like, that didn't even happen on campus anyway: all similar incidents I'm aware of happened in the college town next to campus).