Interesting discussion all-over-the-map.
How many people know that MARS deployed in support of Hurricane Katrina? Natural disaster, comms flooded / broken / etc. Message traffic was flying. In the same vein, the ARES / RACES guys and just plain ol' hams deployed themselves. They set up outside of shelters and people came to send a MARS gram (MARS telegram, ARRL gram, etc) to their loved ones to let them the that they were okay for now.
Wonder what will happen when "the big one" hits California? Hmm-m-m-m
All that aside, MARS still exists, and still meets on the air regularly. I will guess there are about 30 people per average population state. They pass information, and messages, much as they would do in a National Emergency. The bands suck rather spectacularly right now but they will get the message through.
For those that complained about the reams of regulation . . . .

Yes, darn it. They are still using old formats that were originally developed for message centers, etc. There are no message centers anymore, but MARS clings to their Routing Indicators (RIs) like glue. Sigh.
MARS is becoming DoD MARS, though. One service, one communications corps. This is a good thing.
I leave you with a thought. Why does this site exist?
www.netc.comWhy do people that have radioactive seeds implanted, for cancer, have to carry an ID? Why are they pulled over by Border Patrol???
Google "suitcase nuke", and follow some links. What do you know about Electro Magnetic Pulse? (EMP)?
(Good discussion
https://www.quora.com/How-does-an-EMP-electromagnetic-pulse-work-and-what-is-it-effects-Explain-in-details )
We have all kinds of lovely solid state electronics that run the switching stations, the electric grid, all communications. Just think of what will happen if terrorists do manage to nuke somewhere. Who will be left? Go watch Terminator again . . . .