Health risks of firmware-based attacks: Real or tin-foil hattery?

While getting a headache from working with a badly set-up monitor today, I came to the realization that there are other, unforeseen, possibly health-related risks associated with today's proprietary hardware, which is often loaded with locked, closed-source firmware.

There has been some media coverage about 'doctored' firmware being implanted in Cisco routers before they were shipped to customers, and there is proof that hard drive firmware can be altered to modify data read from and written to it. How about the risks posed by more 'mundane' devices like computer monitors?

Anyone who has seen the movie "The Andromeda Strain" probably remembers how an epileptic seizure played an important role in the story. What if firmware in a modern flatscreen monitor were tweaked, before it being shipped to a specific customer, to program the video circuits to emit a seizure-inducing (or hypnotizing) display pattern the moment the person sitting in front of it opens an email message with some innocuous looking graphical pattern in it acting as a trigger?

As I see it, this example and others like it demonstrate the possibility of very specific, targeted attacks on peoples' health. One out of a huge arsenal of possible attacks, which need or need not be specific to one person or a particular group. All of them made possible by our ever increasing reliance on technology over which we have little or no real control.

If the history of hacking and unconventional use of technology has taught us anything, it is that not the things one thinks are possible, but rather the things that one hasn't thought of as being possible, are those that really count.

I'm very interested in your opinions on this matter.