The main pressure on doctors is getting through their long daily list of patients as quickly as they can, and they get their fair share of people who have self-limiting conditions - it's very common for somebody to turn up with a cold (eg a virus) demanding antibiotics, and a rushed doctor may simply find it easier to give them what they're asking for and send them on their way, rather than spend an hour trying to educate the patient, another hour calling in a colleague to give a second (identical) opinion, then dealing with calls from the local MP and patient pressure groups because they "tried to fob off a genuinely sick patient".
Which is why we now have massive problems with multi-resistant bacteria. It's a shoddy state of affairs, and the British public are just as much to blame as the doctors who gave in to their whinging because it was the only way to get them out of the surgery so they could see the child with suspected meningitis.
To cause a real gridlock doing this you have to assume everybody is using the same source of data, and only that one. Most traffic control systems also use mechanical detectors, car-spotting cameras and the like, you'd need to hack all of these systems to guarantee a gridlock.
These days casinos combat it by using multiple decks of cards in a shoe which are changed before they've run through enough of them to give a good statistical idea of the remaining contents.
Lack of access to guns isn't what's keeping the North Korean people in check, proof positive that a right to bear arms isn't a utopian solution to a dictatorial government.
I also regularly search for terms on terms in Qu'ranic Islam (I'm an atheist but find it interesting) and nuclear technology (I'm a physics geek and that's one of my "things".)
The solution as far as I can see is to have really wide ranging interests.