The Max Planck Institute for software systems has released the results of a study on BitTorrent blocking. The research was conducted by asking volunteers around the world to download and run some code on their computers that simulates BitTorrent traffic to test servers controlled by the institute. By carefully monitoring what is happening on both sides of this connection, it’s possible to determine any unexpected traffic shaping attempts.
What emerges is a global map of non-intereference with US and Singapore having the dubious distinction of being the only countries to have sizable fraction of tampered connections. (The percentages are not reliable; it’s quite likely that self-selection lead to many users on Comcast and Cox to volunteer for the experiment.