A couple of years ago, the aerial photo caught our custom combiner's machines sitting where they finished harvesting the wheat on my center pivot.  It was dated a few weeks before the the wheat was harvested.

I visited with a guy running a photo van a few years ago when he was parked about at the WY/CO state line off one of our county roads.  It was not google but he said they sold data to a number of different companies.  Apparently gps software companies use that data for speed limits signs and etc.