 The young shared information and discussed what was happening through the internet. It's one of the unexpected triumphs of social media. When a people rise up against their government, they do it on the internet. On Facebook, Twitter and public blogs. And sometimes after that happens, the government tries to shut the internet down. Twitter has been blocked by the courts. We've seen it happen over and over, from Egypt to Venezuela. If activists are relying on Twitter, a country's central telecom can block Twitter's IP addresses. Suddenly your phone can't reach the server. And if they want to stop online activism at large, they can cut off the internet completely. This blue dot is Syria's exclusive state-run telecom. On May 7th, 2013, it started cutting off the traffic routes one by one until there was no way left to get data in or out of the country. Central web blocks have also happened in Turkey, Ukraine, Egypt, Syria and Iran. The question is, once the connection shuts down, how do you fight back? In the case of a total web blackout, the kind we've seen in Iran and Syria, simple redirect tricks won't work. In that case, you need something stronger, like a mesh network. It looks like this. Each dot is a router and each line is a working connection. There's no need for a central hub or an ISP. No one's ever deployed a network like that in a real crisis, but there are lots of people who'd like to. Today we're going to see what it would look like. New York art space called Eyebeam is hosting a mock internet blackout, kind of a fire drill for the web. Inside, there's no outside connectivity of any kind. The internet is down and we're going to see what kind of network we can put up in its place. The big problem with an isolated mesh network is you can't download anything that isn't already there. But our group came prepared. We're all connected to the local Wi-Fi, which lets us plug in an IP address and connect to a local repo of apps. Using F-Droid and Kripplap, we can download the apps we need to start actually talking to each other. Of course, we're all still in the same room, feeding off the same Wi-Fi network, so once that's done, it's time to make the network bigger. Everything's running on this, a reprogrammed commotion router. It doesn't connect to the internet, it just connects to other routers. With enough of them together, that's all the internet you need. The new network takes some getting used to. There are no centralized services, so instead of Facebook or Twitter, you'd publish using a local WordPress app. Instead of WhatsApp, you'd use a decentralized chat service like ChatSecure or WeChat. Instead of Skype, there's Linfo. After a while, our network broke down. People walked too far away and lost connectivity, unsure of where to set up or how to communicate with the group. Simple coordination is a real problem, and the process is still going through some growing pains. But the idea works. This kind of small-scale network can be useful even if you aren't fighting an internet blackout. Mesh is a big deal in Europe, with immense networks already constructed in Berlin, Athens, and Barcelona. For the most part, they're a way to connect to the internet for a little less money. But they're also vibrant networks in their own right, with files and programs swapped between thousands of different nodes. It's a different kind of web than we're used to, scrappier and less centralized. But that's the whole point. The network in Chicago might look completely different from the one in New York, and surveillance agencies have to move against all of them at once if they want to listen in. It doesn't replace the main internet, it just grows up alongside it, with services that never leave the block. From a global perspective, that's a powerful thing. As this technology spreads, the power of the network gets stronger. Maybe it won't be in New York or Berlin, but the day will come when a government reaches out to turn off the internet, and finds out they can.