Another rant about my school: the default password system.
Each student's username is FirstnameLastname, and the same applies to teachers. The passwords assigned are <First initial><Last initial> for students, and the same for teachers with "teacher" appended to the end. As students, we figured out this system pretty quickly, and we were able to log into the computer system as any teacher who we knew had requested an account. (Teacher accounts had unfiltered Internet access, student accounts did not).
I now teach in this school, where they recently got Google Classrooms accounts for each teacher during Covid. The accounts use the same naming/password scheme! I somehow doubt the teachers replace their passwords, so any student clever enough to figure out the system can log into their Google for Education account.