My 2nd grade teacher accused me of "hacking" the Commodore 64 when she caught me showing another kid how to write a "what is your name" program. (Of course this same school unplugged all their C64s on Michelangelo Day so you can guess their level of tech training.)
I never did it at school but there was always the "fake prompt" trick. Do a few fun things -- throw up fake syntax errors (including transposing characters the user typed correctly) -- print out some rude error message or "formatting drive..." -- and then silently hand control back to the real shell.
You’d be surprised. I bet my elementary school teacher that I could hack their floppy based “email” system once. She felt confident since it had an administrator password.
I figured out that if you removed the floppy before you tried to log in, it would assume you were setting it up for the first time. Then you enter in a new password, put the floppy back in, and hit enter. It overwrote the admin password and poof. “Hacked”. She was not happy. I wish I could remember more details but as you can relate it was a long time ago :)