Over the last few days I've gotten a number of requests to join people on "Spock" which as best I can tell is a social network that crawls the Internet for information about people, so not only can you see what members of your network make available, you can see what information about them is publicly available on the Internet.
At this point I don't see the value in this service, other than if I wanted to be nosy. Given I'm already on Facebook and LinkedIn, I'm not sure I see the value of yet another social network. And I see the real value of social networks in establishing communications between individuals and groups, not in trolling for additional information about people I'm supposed to already know. But, I'll keep my eye on it.
Alec Saunders has posted some of his own observations on Spock's recruitment methods.