David Weinberger (JOHO the Blog: The truth about why I hate Friendster) has “fake but worthy reasons” and “real but unworthy reasons” why he doesn’t like “artificial social networks (ASNs)”:
I am a member of Friendster, LinkedIn, Spoke, Flickr, Orkut, and DeanLink. Friendster aims at dating, LinkedIn at business contacts, Spoke at sales team efficiency, Flickr at photo sharing, Orkut at who knows, and DeanLink at enabling Dean supporters to organize local events. I am equally active in all six, even though one of them is defunct, which tells you exactly how active I am.
The only one I liked was DeanLink, and that was because I wanted Dean to be elected president. All of them suffer from the following problems, to one degree or another. …
Beyond his look at why ASNs are no good, he also mentions FOAF and LOAF, and he finds them good:
LOAF is a new proposal for making available information about social networks. It encrypts your address book and makes it accessible to others. The most immediate application is in fighting spam: If I receive a message from someone not in my address book, LOAF (which stands for nothing, although List of All Friends seems to be catching on) can see if it’s coming from a friend of a friend. …
FOAF and LOAF add value to the Net, enriching it with voluntarily disclosed information about who we are and who we know. In this they are unlike Artificial Social Networks that capture the conversations between us but make them inaccessible to other applications. …