I can’t improve on the Berkman Centre’s blog entry:
An international team of researchers has launched a new program to map censorship of the Internet. The Open Net Initiative — a partnership of the Berkman Center, the University of Cambridge, and the University of Toronto — has formally begun tracking international filtering of the Internet. As the Berkman Center’s Jonathan Zittrain explains, “The aim of the ONI is to excavate, analyze, and report censorship and surveillance practices in a rigorous, ongoing fashion.” Read more about the project in this News Release.