YouTomb, a project of the MIT Free Culture group that studies takedown notices by the video-sharing website YouTube, has identified a mechanism used by Google to restrict video content in specific countries. This appears to be the method YouTube is using to filter videos on behalf of governments and private actors that request it.
The fact that YouTube is selectively filtering videos by location is not new; many of these examples have been reported widely in the press. The YouTomb investigations seem to have uncovered the technical mechanism that YouTube uses to implement this selective filtering, one that can be easily scaled up to block many more videos than are currently filtered, or in many more countries. YouTube is one of the most important global sites that define the emergence of Web 2.0, facilitating the proliferation of user-generated videos in the read/write culture that has greatly increased the ability and impact of participatory media and culture. Given the size and influence of YouTube, the policies adopted by Google and YouTube hold great importance for free expression.