If we're talking about that one developed country where everybody and their grandmother carries a gun, I get the feeling geofencing them would not be a popular measure.
But yeah, in principle this is totally a thing we should do.
We haven’t before now had the technology to do that in a way that wouldn’t violate other rights, but the technology is shifting in such a way that there are domains where we will have that ability and of course we should do it.
The only reason anybody objects to this is because, again, we used to live in a world where you’d have to do something objectionable to achieve these goals, but as that becomes less true the objections will seem increasingly absurd.
Our intuitions in this space lag reality.
Geofencing a car on public roads doesn’t eliminate any legal uses of the car. It doesn’t violate any rights or freedoms. It doesn’t involve any interesting tradeoffs or compromises. It’s a commonsense banality.
This claim shocks people, but that’s just because we used to live in a world where you’d have to do something objectionable to achieve these kinds of goals. But that’s increasingly not true; our intuitions just haven’t caught up to this new reality.
(Obviously, by the way, that’s why your examples aren’t equivalent. I don’t want to chip your brain or your computer, because that would entail an objectionable limitation. Preventing you from speeding in your car on a public right-of-way does not require any objectionable limitation. It only seems like it might, because we’re used to thinking there’s no way you could prevent these kinds of things without doing something objectionable.)