Keep telling yourself that...
They will only do good with their new ultimate power! Nobody in history has ever abused their power...
Hell, you could probably ransom people's cars back to them for more than that.
There aren't that many quality goods and services to spend your ransom money on in prison -- my understanding is that the selection is mainly limited to cigarettes, cell phones, drugs, and "protection".
That is easy, when you flash the firmware on many of the high security types of systems it increments a counter when the bootloader loads the new firmware. they simply look at the counter and see if it matched the last time it was in for an update or was reported on the last update.
It's as simple as a small cheap i2C eeprom hidden away on the system that is not easily read from the running OS. the hacker would haveto disassemble the system hardware and basically reverse engineer the board to discover it. I have seen them hidden under other chips to save board space, but doing that would hide it from most hackers.
Actually most of America would applaud the SWAT team entering banks with shotguns and tasers.
Listening to an investment banker on the floor screaming "dont taze me bro" would pretty much make every single person on the planet smile at the same time. It would cause world peace and make cold fusion work.
Far more OI, better all the way around.
Correcting myself:
Tepco itself has estimated a damage of $137 billion, see http://www.bloomberg.com/news/2012-11-07/fukushima-137-billion-cost-has-tepco-seeking-more-aid.html
Considering the low probability of a serious reactor accident, individual utility companies might bet on not having one in their powerplants and have no insurance unless it is mandatory, like compulsory vehicle insurance.
Set the minimum coverage to something that would cover Fukujima (estimated $100B) and there is your market-based solution
Anything free is worth what you pay for it.