The OpenNet Initiative, a partnership according to the site between “the Citizen Lab at the Munk Centre for International Studies, University of Toronto; Berkman Center for Internet & Society at Harvard University; the Advanced Network Research Group at the Cambridge Security Programme, University of Cambridge; and the Oxford Internet Institute, Oxford University,” has posted an interactive map showing which countries filter or block particular social media sites. Facebook, Flickr, Orkut, Twitter and YouTube are the ones they focus on.
The usual culprits are represented: China intermittently blocks Facebook, Saudi Arabia totally blocks it; Saudi Arabia and Iran block Orkut (they seem to be the only two that care to do so); China and Iran block Twitter from time to time; and Indonesia apparently blocks YouTube off and on.
There are a couple of user-friendliness issues with the map: The pop-up that appears about a country when you hold your mouse over it seems to be too wide for the map window; and it would be nice to have instructions on how to navigate the map for those who aren’t click-savvy.
Not all countries have been tested though; hopefully that’s in the near future.
Other than those picky little things, ONI’s map is a great start, giving an interesting overview on which countries are extending their authoritarian might onto the internet.