Since, ostensibly, it's "you" who has been providing all this content that has been lining other people's wallets, media companies have a vested interest in hyping the idea of defining yourself. But in reality, they're just worsening a bad case of "you" proliferation.

This is why there's been a growing online grumble about "social network fatigue." It's more than a frustration with signing up for umpteen useless accounts; it's the exhaustion that comes from being asked to build an online identity over and over again. Yes, young people have an inexhaustible desire to try on and discard alternative personas like clothing. But the point comes where you say, can't I just be me?

But even as the phenomenon continues to swell, the effort to maintain an active social life on the Web is taking its toll. Some have grown tired of what once was novel. Some feel bombarded by unsolicited messages, friend requests and advertisements. And some are cutting back.

This suggests that as much as people want to connect through the Internet, the practice also can have the opposite effect: social networking fatigue.

"You join a lot, but you don't keep up," said Dave Taylor, a 44-year-old Internet marketing consultant who complained about having social networking fatigue on his blog after joining about 15 sites.

With new social networking sites launching every week, some users have fallen prey to "social networking fatigue," as their inboxes are flooded with dozens of invitations.