I know that Honeywell had computer systems that remotely controlled HVAC for Commercial buildings. (Interviewed for a job as a computer operator.)
The internet of Things. A lot of household appliances use JAVA. (I don’t know it...) If you can remotely access your home’s computer and it can control things like your hot water heater or turn your stove on, then yes. You should have some kind of protection against malware or hacks.
Here is a discussion regarding hacking power plants.
http://www.freerepublic.com/focus/f-bloggers/3687285/posts
Someone, please notify Florence she’s needed up North. Pronto!
I’d be willing to bet the internet of things is running 90-95% on out of the box default passwords. Back when digital answering machines were new everybody left them on default. One of the old hacker/phreaker access methods was to wardial one up, then get into it (this is with no one home) and change the greeting to “Hello...(pause) Oh, yes, sure” and the dial a third party billing into it for their subsequent antics.