Comment by voodootrucker

I can't find a link, but this problem was foreseen and solved by Robert Morris Jr. He wrote a paper on how users could register their location with a 3rd party using a hash of their IP address. When someone wanted to call them, they would contact that 3rd party for the location then route to the cell. The cell knew someone was there, it just didn't know who. And each 3rd party only had info on a few users, and no choice over which ones it had, if I recall correctly.

Looks like there is info here:

https://en.wikipedia.org/wiki/Robert_Tappan_Morris#Later_lif...

This is the way we should have designed these networks from the beginning. It was inevitable that the stuff in TFA would happen, given the interests of the companies involved and no regulation to prevent it. Same with FaceBook and Cambridge Analytica.