This modified floppy drive will eject floppys at high velocity, throwing
them up to 4 meters far. Use it to shoot at your users or install it as a
replacement floppydrive in one of the user machines, then enjoy the show.
Optionally you may install a real strong magnet inside the floppy drive...
the magnetic fields in combination with the rapid movement will have some
desirable (as long as the data on the floppy disk isn't yours) effects.
Epilogue 2016: Yes, I really built those things in the 90s (when VHS tapes and floppys still existed). And they worked.
The VHS tape contains four AA (Mignon) cells and an electric shocker built from a kit.
The floppy had a rubber band wrapped installed inside, which would shoot the floppy out when ejected (really, it reached the 4 meter mark).