Agreed. I wonder if the low orbit solution could be actually more achievable than a standard drone one. Both because it doesn't have to fight the wind all the time and because it can be powered by sun more easily. You need enough power to maintain ~6mph (depends on the area, but I believe that would be the long term average in many places). Sure, there's lift and everything, but you're going to drift in one direction most of the time.
I'm not sure about their availability claims either. "With modern radio transmitters we can get over 100Mbps per node up to 50km away". With modern radio transmitters, I think you can also quickly localise the earth-bound part of the system and either close it down, or create enough interference to make the transfer almost impossible... I'm not an expert on radio though - can someone confirm/refute this?
