Brad Fitzpatrick and David Recordon on the social graph problem:
A centralized "owner" of the social graph is bad for the Internet. I'm not saying anybody should ban Facebook, though! Far from it. It's a great product, and I love it, but the graph needs to exist outside of Facebook. MySpace also has a lot of good data, but not all of it. Likewise LiveJournal, Digg, Twitter, Zooomr, Pownce, Friendster, Plaxo, the list goes on. More important is that any one of these sites shouldn't own it; nobody/everybody should. It should just exist.