I also thought of this and how do military hide from satellites. Do they use powerful lasers to saturate photon sensors. Since military satellites have existed for so long now military probably implemented a way to hide from them.
Most militaries also have access to some high orbit satellites that have 24x7 coverage of an area, and then some low orbit satellites which fly overhead every few hours and can grab high res shots. The combination makes it very hard to sneak a secret plane from one building to another between orbits, since the 24/7 coverage will see it (albeit at lower res).
I'm pretty sure "no" militaries have 24/7 coverage of any area on the planet.