Farcasters what's your answer to this famous YC question: 

Tell us a story where you most successfully hacked some (non-computer) system to your advantage?

Building @kiwi 
Writing @ https://kanfa.macbudkowski.com/

My actual answer was in physics lab, I hacked the Millikan oil-drop experiment using a security camera and laser. Instead of squinting into the eyehole to watch the drops' fall altered by the magnetic field, I arranged the laser to illuminate the drops, and watched them on a monitor with a scale I added with a sharpie.

Not a hack-for-profit, but it made it crazy fast and easy to determine the charge of a single electron.