One of the most interesting lines of inquiry within the Censored Planet project at the University of Michigan is trying to pull apart the different actors involved in Internet censorship. One of the interesting quirks is that a significant factor in why content might not be available to users is that the web publisher themselves have limited who they’ll respond to.
This relates to existing phenomenons like increased balkanization of the web, where regions and nations promote domestic services and networks, but is as much a function of where lucrative markets are and a reaction to the background of fraud and malicious online traffic.
One outcome of this research is a set of measurements looking at how and where CDNs limit access, that will be presented tomorrow at IMC.
Like many parts of the Internet, a take-away here is that attribution is hard.