Similar situation. I would suggest installing an implant that needs to be re-armed every month or so, and if not it releases some toxin that causes a natural-seeming shutdown. [1]

No, wait, that's _insane_. What the hell is wrong with people?

In this thread, SaltySloth's comment [2] is most prescient and provides the best practical advice.

[1] https://news.ycombinator.com/item?id=29430888 [2] https://news.ycombinator.com/item?id=29430583