No doubt cyber warfare to some extent the holy grail of modern weaponry. Theoretically, it could disable opponents' nuclear arsenal.

The internet is an interesting question though. As long as you have the electricity to make devices run, they can connect to each other. The domain name based Internet as we know it is made possible by a network of DNS servers, but those aren't absolutely necessary. Without a DNS network, we'd have no domain names, so no formosahut. But we'd still have IP addresses. DNS servers map domain names to an numerical IP address. IP addresses are what the whole system is really based on.

While in Taitung, one sort of fantasy project I had was to create an intranet of sorts. Any community of users does not need an ISP to connect to each other. All they need is either a hard-wire connection or wifi (over any sort of distance, that would require strong boosters), and at least one serving as a server. The internet protocol makes it possible for any computers to communicate, given they have the requisite software installed.

Another hobby that I've never realized is short wave radio.

And then there's Morse Code.

And smoke signals.

Pigeons.