[laurent92]

Could you have pinged a server that only existed on the public wifi, and made the public wifi keyless?

[twodave]

An actual connection is not necessary for wifi to contribute to location accuracy. It just uses signal strength to available access points to triangulate. How folks like Google/Apple/etc. are able to get accurate location data for those access points is unknown to me.

[judge2020]

https://www.zdnet.com/article/how-google-and-everyone-else-g...

https://support.apple.com/en-us/HT207056#:~:text=If%20Locati....

TLDR Android & iOS Location Services will automatically contribute wifi data and correlate it with GPS. This can be audited to prove it's anonymously uploaded but it does happen.