The law as written provides the rules of the game. Nobody should get to cheat, not the government, not a citizen, not a business, just because someone can plausibly argue that if the law were rewritten today it'd be written differently.
If the claim is true that the law would be and should be written differently today, then: Rewrite. The. Law.
If you don't have enough public support for that, then you have no business imposing your view on your fellow citizens. If you do have enough public support, but Congress is being dysfunctional (this is usually the case today), then communicate with your congresspeople and/or try vote them out, and persuade your fellow citizens to do the same. Don't cheat at the game. Play it.
It sure feels like the game is rigged against regular citizens already, though.
Now, to be fair, those polls aren't asking people about location data specifically. I'm open to seeing specific polling on this issue. But based on the lack of any political will to do anything about TSA, my suspicion is that "regular citizens" are okay with the police using location data to catch bank robbers.
So maybe your "the game is rigged" point cuts the other way. It's rigging the game when fancy lawyers make complicated arguments about what James Madison would have thought about geofencing, in an effort to impose shackles on the police "regular citizens" never voted for.
If we don't want the government to be able to do that, we should pass laws to that effect.
Though again, making no judgment as to whether or not it should be allowed. I just think it should be a law, and not casting modern values on the 1700s era founders' words.
I'm also pretty sure they would be 100% horrified by what it has become.
So yes, it should be law. The US supreme court however does not make laws (or at least, they shouldn't be), they interpret the constitution. And the US constitution is well overdue for a more tech aware version, it's just that with the lawmakers apparently in the pockets of the tech billionaires I think that the chances of such an overhaul approach zero.
I suspect you're right--a bunch of high-IQ libertarian men who had just overthrown their government would write the 4th amendment differently if confronted with universal digital surveillance. But is that how we decide the legal effect of the constitution? We're stuck not only with what the founders actually wrote, but what they would have written if confronted with modern facts?
What are the parameters of this analysis? Do we assume the same James Madison--we have transported him into present day with his knowledge and thought processes intact and are simply presenting him with additional facts? Or do we assume a modern James Madison--the same kind of person today that James Madison was back then. And who decides what reincarnated James Madison would or would not have done--and why do we trust that this medium is correct?
I think it's simpler to say that the meaning of the constitution ends at what is written. What the founders intended is relevant to the extent we're trying to figure out what what they meant, at the time, by the words they used. But we won't go so far as to speculate about what the founders would have written if confronted with modern facts. We have people who can decide what to do about modern facts: they're called voters.
This is a bit of a specious argument, though, since of course what they wrote often didn't clearly articulate what they necessarily meant. You even point this out above: what is ownership, and what is unreasonable? Does entrusting your effects to a third party for safe keeping make them less your effects, etc.
Sure. But what "they necessarily meant by the words they said" is different from "what they would have said if confronted with different facts."
The ownership issue is a good example. Does the word "their ... papers and effects" include third-party data about someone? Third-party data existed in 1789. British people love record-keeping, and the founders were sophisticated people with lawyers, accountants, merchant accounts, etc. If the fourth amendment meant to include third-party information about someone, the founders wouldn't have used the ownership language that they used.
So the real argument is that, if the founders saw how important and sensitive third-party information is today, they would have included it. They wouldn't have used the ownership language they used. That's quite a different argument! It's not just trying to understand what people meant by the words they used. It's trying to reanimate them and ask them questions to scenarios they never contemplated.