Hacker: Technical innovator, or cyber terrorist?

I'm putting it out there. In the past 5-10 years hacker started to get used to describe people repurposing hardware, or crafting their own inventions from basic parts. Or, commonly in software, where one can 'hack' together something relatively quickly, usually using existing parts: recombination. This term, used in this way, is creeping into mainstream media, which is pretty cool.

Outside of the IT circle, to 95% of the population, a "hacker" is someone who breaks into things, stealing credit card information and wreaking untold havoc on civic infrastructure. Journalists seem to be in an awkward space where they have a term to describe two vastly different things, either: a) a buzzword in the case of hardware tinkerers and b) a scareword in the case of software breaching. This is potentially leading people to think electronics enthusiasts are taking down the power grid, and that people who breach large corporate databases are now building homemade UAV's to do their work.

As an example (of which there are not few):

Car hackers use laptop to control standard car

http://www.bbc.co.uk/news/technology-23443215

"Two security experts in the US have demonstrated taking control of two popular models of car, while someone else was driving them, using a laptop."

In actual fact, they're using the diagnostic port on the car, it's not like some unscrupulous hacker can suddenly take over any car just because it was driving past.

This weekend I'll take my mother for a drive, I imagined my mother quizzing me in the idle chatter as I drive: "Scary world. Have you seen that they can hack into and take control of your car now?"

sigh

So I finally decided to raise the question I have around this:

Do we worry about the risk of homebrew technical innovation being inextricably linked to cyber theft and terrorism?

What can we do to prevent/help/avoid it?