I went to an engineering college. The administration seriously underestimated what a group of young, rebellious smart people with a lot of free time could do.
The washers and driers in the laundry were a favorite target. They tried a variety of coin and token mechanisms - all hacked or counterfeited.
As I remember it they finally got a system where you paid with a plastic card that had etches like a circuit board. After the card was accepted the machine melted the card before dumping it in a bin. We moved on to lower hanging fruit.
My personal best was ‘studying’ the payphone on the dorm floor. The installer thought it would be a good idea to leave the small patch panel for the cabling exposed.
Turns out one of those wires provides power to the motor that routes coins to the outside return or inside lockbox.
Hypothetically, if you disconnected that wire all the deposited coins would stack up in the tube. Reconnecting the wire, depositing a coin and then hanging up would return your coin plus all the others stacked in the tube.
Not sayin anyone would do such a thing, but you really shouldn’t leave wires exposed.