In the U.S. alone, nearly half of us have a Facebook page. Each day a tremendous amount of personal information is added to the site.
But Consumer Reports cautions some of that information can be used against you...and in ways you might not even imagine.
Attorney Kevin Jolly was shocked when he found someone had created a fake page in his name and used it to send messages to his friends.
Jolly says, "He portrayed me as a very flamboyant gay man who wanted to share his sexual desires in a very, very, graphic way."
Jolly says he quickly contacted Facebook but it took several emails and almost a month before the imposter profile was removed.
Problems with Facebook are on the rise, up 30% in the last year, according to a Consumer Reports National Research Center Survey.
It was conducted in January among a nationally representative sample of 2,002 online households.
Kim Kleman of Consumer Reports says, "We estimate that seven million Facebook users ran into trouble in the past year, everything from someone using their login without their permission to them being harassed or threatened."
Furthermore, Consumer Reports says some of the personal information widely revealed on Facebook can come back to haunt you.
An estimated 4.8 million posted where they'd be on a certain day-a tip-off to burglars
4.7 million "liked" a page about medical conditions or treatments, details a health insurer might use against you.
Kleman says, "Employers can also look for clues in wall posts and photos that may play into whether you get hired."
Consumer Reports says the government is also peeking at your data...for instance, this 2009 IRS training manual shows how to use social networks like Facebook to "assist in resolving a taxpayer case."
You can restrict who sees your Facebook wall posts and photos by updating your privacy settings. But 17% of current members said they did not use them, according to the Consumer Reports survey.
Privacy controls are particularly important for kids on Facebook to head off stalking.
Consumer Reports estimates 800,000 minors were subjected to some type of cyberbullying in the past year.
Children under 13 are not supposed to use Facebook.