Google and Apple both have WiFi geolocation databases. As far as I can tell there's no way for an AP to opt-out of Apple's database.
Interesting tidbit from [1]: "In older versions of Apple's mobile OS (1.1.3 to 3.1), Apple relied on Google and Skyhook Wireless to provide location-based services -- so Apple left data collection to them. But ever since April 2010, starting with iPhone OS 3.2 and continuing into the current iOS 4 software, Apple has started using its own databases to provide location-based services to iOS devices."
I remembered that Apple has such a database too, and interestingly, here's a project that reverse-engineered queries to Apple's Wi-Fi geolocation service: https://github.com/zadewg/GS-LOC
Particularly someone asked whether Uber could scale the approach. I couldn't find how many cities in which Uber uses corrected GPS, except a 2018 Verge article that says "15, launching soon globally". Either way, seems like the answer is Google has the data to do it. And Google can bring it to every (non-China) Android phone.
But yeah, Google's post is very light on technical details. It'd be interesting to see if their approaches were similar.
Edit: also of note, Uber used server-side correction (at least in 2018), while Google downloads 3D tiles to the device.
Correct me if I'm wrong, my read is that this is a competitor to Google's external BeyondCorp solution[0]? (They reference the BeyondCorp papers in the post.)
> The employees revolted so strongly the project was cancelled.
Exactly - the buck stopped at company leadership beholden to internal/public reputation, rather than a central authoritarian government with the power to make you disappear.
Context: All internet companies in China operate under China's Cyber Security Law [0]. Among its consequences: "Companies could be asked to provide source code, encryption, or other crucial information for review by the authorities".
(Tangent: TIL Apple's operation of iCloud in China is by a government-sponsored data company named Guizhou-Cloud Big Data [1] as a result of this law.)
[1] https://www.sonobus.net/