Police were called to dismantle a secret cryptomining rig winding throughout the floors and ventilation ducts of a Polish court in September, according to Polish news channel TVN24.
Several secured computers were discovered, potentially stealing thousands of Polish Zlotys worth of energy per month (the equivalent of roughly $250 per 1,000 Zlotys.) It's currently unknown how long the rig was running because the illegal operation went undetected, partly because the computers used were connected to the Internet through their own modems rather than through the court's network.
Rambler wrote
Well, not paying for power is one way to achieve profitability.
I always assumed this sort of thing likely occurred in industries where there is massive power consumption already where a rig or two may go undetected.