Another lesson from Somalia, besides gangs trying to hijack food relief supplies, is that even in hell-holes, they will still have cell phones. Even today, in Somalia, you can make calls and send texts. Or in Afghanistan, for that matter.
They may have cell phones in hell-holes, but in a TSHTF situation, the government could order the cell networks shut off in no time. With no network, those cell phones are just high-tech paperweights.