and then we come back to one of the original missions of the NSA, which was to intercept international telephone call/data/telex traffic that had no terrestrial intermediary, between two different C or Ku band geostationary earth stations in two different locations of the world which were using a geostationary transponder as a relay point.

If it's flying through the air and somebody really wants to grab it they will, whether they can read it depends on how good your crypto is.

https://en.wikipedia.org/wiki/RAF_Menwith_Hill