You read Part I here.

5. It could make you depressed. Researchers from Stony Brook University in New York found that teenage girls who spend the most time discussing their lives with friends were more likely to be depressed. Apparently, spending too much time dwelling on gossip and your problems can make you feel worse, not better. The researchers didn't study Facebook in particular, but they indicated that social-networking sites such as Facebook made it easier for people to be in constant contact with friends and perpetuate the unhealthy discussions.  

6. It can cost you a job. A British survey of employers found that half of those polled had turned down job candidates once something unsavory about that candidate surfaced on Facebook. (Examples include tales of drunkenness, photos of illegal activity, and bad grammar.) In the U.S., 20 percent of employers admit to scoping out the Facebook pages of potential job candidates, while 9 percent say they're going to start soon. 

7. It can out you to your family.  Even if you're discreet on Facebook, your loose-lipped friends might not be and could post comments on your wall that betray your secrets. But there are also more insidious outings going on: MIT students designed an algorithm that successfully pinpointed gay users by analyzing how many of their friends were gay.

8. It can make it easier for your stalker or abusive partner to follow your movements. Let's be honest: if there weren't Facebook, abusers would find another trigger to set off their rage. But Facebook has made it easier for these people to keep tabs on their victims and respond to their movements, even after the victim has tried to sever ties. In one particularly sad case, a woman who changed her Facebook status to "single" was killed by her husband, from whom she had separated. After seeing her status, he broke into her home and stabbed her repeatedly. 

9. You can be sued for libel. There are already several cases of libel suits over content posted on Facebook. In Britain, where libel is easier to prove than in the U.S., a businessman won £22,000 when a former classmate created a fake profile full of defamatory information. Stateside, an Ohio-area band sued a Facebook "hate group," and a Michigan towing company sued a student who created a Facebook page alleging that the company tows legally parked cars. (The company says those claims are false.) So far, the law appears to be on the poster's side. But it's still a hassle.

10. Your kids could be targeted by predators. After a teenage girl in England was murdered by a sex offender who posed as a teenager on Facebook, the British version of the site added a "panic button" that allows teens to report any unwanted attention—including cyber-bullying—directly to the authorities. But the button is not yet on U.S. or other international versions of Facebook, and it's unclear whether the company plans to add it.