When disaster strikes, communication lines are destroyed. An ad hoc communication system can be formed which provides telecommunication.
While in the current metropolis, it is often illegal or unlikely for people to share their wifi, their cellphone or their power. During an emergency these notions of selfishness are losened or lost.
A crowdsourced wireless text messaging service could be built and maintained by community members for such occasions. It could be low-power and designed to run on a small percentage of an individual's batery power reserves.
Category of the action