There was a warrant in this case. That type of warrant is now deficient and electronic data holders like Google with easily refute future attempts to get data with a clearly deficient warrant. Parallel construction typically means a warrant was not given on the first pass.
Without speaking of the general case, this specific legal precedent does prevent parallel construction for this particular source of data.
In order to obtain the data that law enforcement would have to "discover" through parallel construction, they need Google to cooperate and run the analysis to give them the required data. They can try to make this request through informal channels, but Google will say that they need a warrant. They can't make the request through formal channels because no judge will give them a warrant. So that's pretty much it.
So now we just have to rely on Google/Apple/cell-carriers to not hand over all the geofence data without a warrant. I'm sure the cops will be leaning _heavily_ on 3rd Party Doctrine next time they call up Google with their warrantless geofence data requests.
Interestingly, Google has recently started to shift their entire infrastructure for location tracking off their servers and onto users’ devices. Motivated in part by geofence warrants (and, in this commenter’s opinion, perhaps by anti-abortion laws in the US too).
It’s actually rather frustrating for me as I used to export and keep the GPS logs, for geotagging photos from a camera, which will need to be done per day now. Nonetheless, a smart move as they simply won’t hold this information anymore - even for those who opt-in to the feature.
While I'm in favor of restricting warrants in this way, it is important to realize that it will result in some crimes being unpunished, and potentially even deaths.
There is a cost to living in a free society that needs to be recognized, even though it is still a cost worth paying.
Parallel construction is this huge phantom menace on the internet but something that in real life occurs less frequently than a person being struck by lightning.
Law enforcement faces a very high burden to show that parallel construction would apply. (Not "could." Would.) This generally requires law enforcement to show that they were pursuing multiple parallel paths of investigation, and that basic investigatory work in one of the other paths of investigation would have legally led to the excluded evidence as a matter of course. To put it perspective how difficult this is, a former co-worker that is still with the public defender has seen the prosecutor succeed exactly once in 15 years in making a parallel construction argument.
The DEA is the only agency that successfully makes parallel construction arguments on a regular basis, and this is primarily because the DEA has the resources to actively pursue multiple parallel paths of investigation, and because in many cases the reason for using parallel construction is that key witnesses have a tendency to get murdered....
Well they need the warrant to get Google to give them the information in the first place, so they would not have the data to create the parallel construction.
I'm confused how parallel construction plays in here, nonsense adds another layer of confusion, but an attempt to help, tl;dr: the 5th Circuit has held that requesting a list of people/IPs/devices in a location is not permissible.
I'm just trying to guess a gap: engineers tend to see law as more iron, like code, and judge law based on inverse programming: if you can find some set of circumstances that creates a gap where the law isn't obeyed.
Ex. here, you might mean that this doesn't technically stop police from requesting geofenced data anyway, using it to get suspects, then not mentioning it at trial. Yes, technically, the police could ignore this, and request a warrant, then the judge could ignore it, then the tech companies could ignore it, the DA could collude with the police to hide that happened, and pretend they found the suspect a different way.
But it's impractical.
It's hard to spell out why, exactly, tl;dr: death penalty for your career if any of this is discovered by anyone, you can't do it by yourself, and these people are generally on the same team in our distanced analysis, people are tribal, and gov't attorneys/tech companies/judges/police can't rely on eachother's silence.