The article "Can You Trust a Facebook Profile?" describes the "surprising truth" that "Overall people were remarkably honest in representing themselves":
People were honest—we don't read those words often enough.
In line with other findings, this study found that, when looking at a stranger's profile for the first time, some aspects of personality are more difficult to discern. Neuroticism in others is particularly difficult to gauge, whereas people find extraversion and openness to experience relatively easily to assess, even in strangers.
This study is another blow for that old stereotype that the web is some kind of scary hinterland, an untrustworthy place where anything goes and nothing is what it appears, peopled by adolescent boys pretending to be anything but adolescent boys.
I have long thought that key to online honesty and general good behavior is tying activity to real identities. There is a major difference between what you are willing to do behind a handle (like a message board or chat name) and what you are willing to do on a site that is connected to your identity (ie Facebook, PayPal, etc). It is even more pronounced when the identity is fully public. For instance, I believe you are now less likely to misbehave of Facebook now that content is increasingly public, URLs are indexable and you have a personalized domain (ie http://facebook.com/ryanspoon).
For years I have gotten the question about beRecruited (a college recruiting network that I founded in 2000 - now with 750,000+ athletes): "how do you police athlete's 'resumes' and results?"
My answer is simple: because athletes register with their actual name and personal information (school, coach, guidance counselor, etc), it self-regulates. Sure an athlete can falsify results - just as anyone can on their resume - but such actions have life-long implications and are easily disproved. For example, this is what keeps LinkedIn clean and makes it so effective.