Time for Americans to study up on these kinds of things:
http://www.bing.com/search?q=clandestine+cell+system&FORM=HDRSC1
That cell world can be penetrated in todays world. Data mining, metadata, etc. Better to lose the need for a system that coordinates at all. Leaderless resistance to a well understood goal is the “go to” method.
Assuming of course, that a hostile enemy had occupied America and needed to be resisted.