This map makes it seems hysterical to me that people think it's being done as espionage and is a national security issue. The land is wide open and easily observed. In any actual conflict anyone operating in that area could easily be shut down. And just look at the map, it's an awful lot of land to just "spy" on a military base, a lot of the land is as far as 20-30 km away.
This land is all filling out a very good area for wind power generation, so I'm guessing they have plans for a lot of wind farms.
EDIT: If you go to https://globalwindatlas.info/en you'll have no trouble finding the area on a view of CA. It's one of the bright red areas between SAC and OAK and this land conveniently fills most of it.
Does that say what billionaire is funding the purchases? I'm not familiar with that DB but the info for who is actually behind the company (vs just an agent of it or a lawyer or whatever) seems non-obvious
(edit: for reference, this is what I see https://ibb.co/M2dDBZ1. The address is just a mail forwarding service.)
This land is all filling out a very good area for wind power generation, so I'm guessing they have plans for a lot of wind farms.
EDIT: If you go to https://globalwindatlas.info/en you'll have no trouble finding the area on a view of CA. It's one of the bright red areas between SAC and OAK and this land conveniently fills most of it.