>>1735>ad hoc meshnets
setting one up before hand is probably nice, but simply having the software and documentation on hand to build one if things turn bad, is not at all difficult. my neighborhood does (sadly) not have a meshnet running at present, but it could have one within a few days of a blackout just with the resources I have in my house, and some extra routers.
I need to read more of the Arab Spring things, a fascinating topic about which I know too little.
One thing I have also been considering (in light of several recent large disasters) would be the possiblity of setting up a meshnet within a recovering disaster area (Puerto Rico of right now, as an example). If the phone and ISP nets are damaged to a high level, that might be about the best chance one could have to establish a meshnet on a large scale with the participation of nongeeks. >>1715
I may misinterpret your term: sharing network.
in the case that I dont, I would posit that there is a great amount of data being shared, and collected, in many many nodes the world over. I on my own disks have more than a few websites, a fair ebook library, quite a large amount of software inclusive of sourcecode, news archives, among other things.
Presently this is not available to the wider world, I havent the interest, the bandwidth, or the need to make it accessible outside of my network. If suddenly my country were to impose strong restrictions on the internet, there would be motive for me to make that which I have collected useful to other people, and whether its by a sneakernet, hidden service, local meshnet, or other scheme, I would do what is in my power to share that which has been shared with me.
I would do so, and I am sure there are many other people in the world with similar mindsets. These archives are not visible today, but in the event of a disaster, they will doubtlessly emerge.