One tech that I have yet to see explored: We know that the police have these marvelous high-power video-telescopes in their copters. Given all the motion and vibration, they have to have some amazing image stabilization.

With much lower quality stabilization, it should be possible to aim a modulated laser, such as a $200 200mW green laser pointer, at a fixed surface, such as a billboard or convenient building wall. Someone else could “tune in” to the laser by simply aiming a telescope at that point. If you had a feedback loop to keep the reflection centered, then you could have very high bandwidth communications, and, if you used UV or IR, it might be very hard to detect, much less decrypt.

In fact, if you had something conveniently high in the sky, such as a mirror-surface tethered dirigible, say, as a backup to the satellites being knocked out, then the entire bandwidth of the L.A. area could be handled that way. No fiber, no copper, just fairly low-powered modulated lasers sending signals point-to-point. (Of course, weather could be a problem… Weather? WEATHER? We don’t need no STINKIN WEATHER! (Eat your heart out – non Californios.))

Might be useful to your upcoming sequel’s terrorists…