A teaching seminar was held in one of the classrooms that I took a class in. Students came in the next morning to see a username and password on the whiteboard. It didn't take long for us to test it on school computers.

The account had admin level access and could go into any student's directory. This led to rampant cheating on homework and labs.

I used it on my physics labs in senior year. I, and a few others, were caught and had to make up a few of the labs in the early morning in order to be able to take our finals. Also had detention for weeks.

A year later, after I had graduated and was in college for CS, I applied for a job at the school as a system administrator. The guidance counselor was in the room when I was talking to the IT admin. When I left, she brought up how I had broken policy and accessed files via that breach. The IT admin found me in the hall and asked me about it. I explained that I had taken my punishment, made up the labs, and didn't feel that it would affect my work at the school, but would withdraw my application anyway.