Killing people. Imagine a StuxNet type attack that targets medical equipment or an attack that can drop planes from the sky (https://www.wired.com/2015/05/feds-say-banned-researcher-com...)
> I would second guess anything that uses a computer to keep a record of something that someone would have a direct benefit if manipulated
Then you better move to the woods. Basic economic principals (scarcity) mean that every resource has value to an interested party.