I have deleted all of my social networking accounts due to privacy and spam concerns. Your mileage may vary, but as much as I enjoy online networking, there is no substitute for meeting face to face. And there is no denying the fact that the majority of the email I received from social networking sites was the functional equivalent of spam.
(2004-02-10) (http://www.theregister.co.uk/content/6/35443.html)