Isolation, loneliness and low social status can harm a person's subjective sense of well-being, as well as his or her intellectual achievement, immune function and health.

CNN: The importance of belonging

The social-networking service being considered would incorporate and go beyond Buzz, according to one person familiar with the matter.

WSJ: Google Develops a Facebook Rival

For most social-networking sites, the data identified the profile being viewed but not necessarily the person who clicked on the ad or link.

WSJ: Facebook, MySpace Confront Privacy Loophole