Internet side effects

A friend came over today. We were talking until I got the internet set up at my new home. And then there was silence. Makes we wonder:

• How has the internet changed attention span?
• Are social networking and the internet sufficient to replace "offline social experiences"?
• Do power users of the internet burn out quicker at jobs that require extensive use of computers i.e. most jobs?
• Can digital ever match or supersede the serendipitous discovery process that happens offline?
• Are power users of the internet asocial in face to face settings?
• Do power users of the internet have withdrawal symptoms when they are away from their devices? (Compulsively checking email, facebook, twitter what have you)