But of course "access to a repeater" violates the part of "with no centralized infrastructure to fail" in the parent's post. But one also has to distinguish ol

But of course "access to a repeater" violates the part of "with no centralized infrastructure to fail" in the parent's post. But one also has to distinguish old-school repeaters covering a medium-diameter area from the worldwide, internet-connected relays (such as IRLP). Whereas the former are easily put up freestanding on an amateur budget, and hence will stay in operation independent of all the other infrastructure, the internet-bound systems will cease operation once the internet links break down.