I took 'could possibly' + reference to cell service to mean that there is some sort of technical/infrastructural limitation. If your point is that the world is

I took 'could possibly' + reference to cell service to mean that there is some sort of technical/infrastructural limitation. If your point is that the world is big and any effort to do this would take a long, long time to fully penetrate beyond a few highly developed Western countries, then I definitely agree.