Your example isn't a great one because it requires localized access to individual vehicles. Thus the maniac has to be local. With the new Chrysler issue the maniac doesn't have to be anywhere near the vehicle. I can think of more than a few groups world wide that would love to suddenly disable the breaks on ~500,000 vehicles. Its also going to be harder to notice failing breaks a head of time when they suddenly stop working while you are on the highway
I agree, my example was "limited" in scope. Increasing the range, makes it more worrying
The news now seems to be saying that they can be hacked, simply by sending a dab radio signal (i.e. a normal radio station signal), which e.g. Can totally disable the brakes, suddenly, with out warning, on a huge number of vehicles at the same time.
http://www.bbc.co.uk/news/technology-33622298
Car hack uses digital-radio broadcasts to seize control
Several car infotainment systems are vulnerable to a hack attack that could potentially put lives at risk, a leading security company has said.
NCC Group said the exploit could be used to seize control of a vehicle's brakes and other critical systems.
The Manchester-based company told the BBC it had found a way to carry out the attacks by sending data via digital audio broadcasting (DAB) radio signals.
It coincides with news of a similar flaw discovered by two US researchers.
Chris Valasek and Charlie Miller showed Wired magazine that they could take control of a Jeep Cherokee car by sending data to its internet-connected entertainment and navigation system via a mobile-phone network.
Chrysler has released a patch to address the problem.
However, NCC's work - which has been restricted to its labs - points to a wider problem.
This is a more worrying development.
The problem is, someone could be mad enough to publish the full hack details, on the internet. (Much of the info has already been released, as stated in the earlier article).
So it could be a bit like those fools who mess with aircraft/helicopters, by blinding them with powerful (readily available) green laser pens. Or the incidents when drones etc fly towards civilian aircraft, posing a danger.
But the hackers would be restricted to a limited practical range of a mile or few miles, if they bought/built a private transmitter. Otherwise they would have to somehow hack into the bigger radio networks, which would NOT be easy (hopefully!).