Roger Dingledine and Jacob Appelbaum will talk about how exactly these governments are doing the blocking, both in terms of what signatures they filter in Tor (and how we've gotten around the blocking in each case), and what technologies they use to deploy the filters -- including the use of Western technology to operate the surveillance and censorship infrastructure in Tunisia (Smartfilter), Syria (Bluecoat), and other countries. We'll cover what we've learned about the mindset of the censor operators (who in many cases don't want to block Tor because they use it!), and how we can measure and track the wide-scale censorship in these countries. Last, we'll explain Tor's development plans to get ahead of the address harvesting and handshake DPI arms races.