The difference is, the rich and powerful do their crimes with lawyers. A contractor could actually write something into their contract that allowed them to install such a kill switch. And it would be perfectly legal. No different than if you stop paying for a software license and the program stops working. But regular employees don’t have the leverage to demand such a kill switch. Maybe more programmers should form unions. Write it into the contract that if the contract ever expires before a new one is signed, the union has the right to remotely activate a kill switch, shutting down crucial operations within the company. As long as this was all disclosed and signed to, it would be perfectly legal.