Social media affecting teens' concepts of friendship, intimacy

Young people feel socially supported by having large networks of on-line friends they may never see. 

Social media is affecting the way kids look at friendship and intimacy, according to researchers.

The typical teenager has 300 Facebook friends and 79 Twitter followers, the Pew Internet and American Life project found in its report, Teens, Social Media, and Privacy.

And some have many more.