NPR report on an Iran based myspace/itunes site shares music by underground (and rather illegal) artists. The profiled song, I Shot You Babe, is a remix of Sonny and Cher's song, with gunshots in the background. The artist DJ Foundation, is cloaked in Banksy-esque anonymity.
In keeping with the xkcd love, here is the updated map of the internet (or online communities) If I had to pick a public space out of the internet, it would probably be Facebook, which is by far the largest on this map.