Defense Department consultants, Travis Taylor and Bob Boan, have published a plan for an earthling uprising against invading space octopi. Their outline for anti-alien guerrilla struggle appears in their book, An Introduction to Planetary Defense: A Study of Modern Warfare Applied to Extra-Terrestrial Invasion.
So should you be building your bunkers in the woods and studying up on how to blow little green men to smithereens? At least some analysts believe that the likelihood of such an attack is remote.
As for me, I'm more worried about a future robot uprising.