What would we do if an attempt by hackers or an enemy state to take down the internet would succeed? Even though the internet is essentially a huge decentralized network of cables, the DNS structure is not so decentralized and has already been target of attacks. Even this week, a distributed attack on Dyn's DNS caused many US visitors unable to reach popular sites like Twitter and Github.
There are also governments that censor sites like Twitter and Google for political reasons. People have a natural wish to share information, and this question is really about how this can be facilitated when common social network sites are down.
How could we share information?
When the internet is down, but the infrastructure is still up, we might still be able to access each others computers, if we know their IP addresses. If even that is not possible, we may have to go back to handing over storage or visiting each other with our laptops.
What would we want to share?
We produce bits of information every day. Some of us tweet small messages on Twitter, others post photos and short notes on Facebook. Some people write bigger blog posts or even articles for newspapers. Some of these posts are shared with the whole world, others only with our best friends.
Then there are pull and push models. For a news article or a blog post, the reader has to do some effort to look it up, i.e. pull the information. In the case of a timeline or especially an e-mail message, the content is very clearly pushed to the recipient.
What is missing?
What we need is some sort of standardized way to package bits of information making up a blog post, a photo or just a shared, 'liked' URL, and to copy them around without using the internet. Creating a local HTML file sound too clumsy for practical purposes, but a locally running application that would create this and allow us to share them in a user friendly manner might work. Think Facebook, but without Facebook. A locally running application would be able to import these posts arriving through LAN or even a USB stick, and allow us to select what we need to save locally.
When the internet is down for some time, it is likely not to be the only problem we have. It may be part of (geo)political unrest. We may want to communicate not only with our circle of friends, but with all the people in the country and the world. Whatever solution we find, it needs to offer a transitive solution to re-share things to second and third level connections.
We want to ensure the ideas of a dissident won't go missing when the dissident does.