Unfriending Facebook: more than 900 million people are on the social networking site. But in the U.S., some young people are just saying no to Facebook.

• Author: Majerol, Veronica
• Position: MEDIA

Ashleigh Elser walked away and got drawn back in twice before calling it quits for good last October. There had been good times, the 25-year-old says, but in the end she decided her life was better off without Facebook.

"I wasn't calling my friends anymore," says Elser, a graduate student at the University of Virginia. "I was just seeing their pictures and updates."

Founded in Mark Zuckerberg's Harvard dorm room in 2004 and initially open just to college students, Facebook is the largest social-networking site in the world. It was worth more than $100 billion when it began selling stock to the public in its much-anticipated initial public offering in May (see "Facebook & the Stock Market"), and it has revolutionized the way people keep in touch with friends and family, share photos, and discuss politics and pop culture. It also played a key role in the protests that toppled several autocratic regimes in the Middle East during the Arab Spring last year.

But while Facebook may now seem a nearly ubiquitous part of modern life, there are signs that Facebook fatigue may be setting in, at least in the U.S. In a recent Associated Press-CNBC poll, more than 50 percent of Americans said they think Facebook is a passing fad. And the rate of new users joining Facebook in the U.S. is slowing: annual growth is at 6 percent this year, versus 39 percent two years ago, according to eMarketer, which tracks Internet traffic. Then there are those, even on the younger end of the age spectrum, who refuse to try Facebook or have tried it and left.

Why They Quit

For some users, privacy is the main concern. Over the years, Facebook has faced questions over how it handles the vast quantity of data it collects from users and how much control they have to delete their own content. For others, it's simply a matter of not wanting the whole world to know about everything that's going on in their lives, from the serious to the mundane.

Zach Petersen, a 19-year-old sophomore at the University of Tampa in Florida, was on Facebook for four years before deleting his account in April. The final straw: He had just bought a new car and posted a picture on Facebook for his friends. Suddenly, everyone he ran into on campus--including people he wasn't connected to on Facebook--seemed to know about his new wheels.

"It's just kind of strange knowing that everybody knew about it," he says. "A friend of a friend of a friend can see your stuff," even if "it was intended for you and...