When I studied they had some small coursework you had to do in the first few weeks to indicate you understood what plagiarism was so there were no excuses if you got busted. Perhaps something similar for backups would be good.

I lost data on the weekend whilst trying to resolve differences between directories on machines. I was using meld (at 2 o'clock in the morning) and clicked 'delete' on a selection when I meant to click 'right'.* Spent several hours after that scanning sda1 for byte segments resembling the beginning of xlsx files (no luck). Serves me right for using dumb binary formats that don't lend themselves to diff-based source control.

* Brilliant the way the app places those buttons right next to one another.