On the flip side, if your device resists your attempts to run cat_pictures_infected_with_cryptolocker.jpg.exe, it is clear that somebody else has some degree of control over the behavior of your device, and this somebody does not consider you to be the sole legitimate controller of your device.

Who is this somebody, and what right does he/she/they have to retain partial control of your property? That sounds like a more interesting question to me. Because unless you're like RMS and only use free software on open-source hardware, you're never the sole legitimate controller of any device these days.