A new survey shows how some of your personal information on Facebook can be used against you

(WXYZ) - Almost half of us have a Facebook page. Each day a tremendous amount of personal information is added to the site. But problems with Facebook are on the rise, up 30 percent in the last year, according to a Consumer Reports National Research Center survey conducted in January among a nationally representative sample of 2,002 online households.

Consumer Reportse stimated that 7 million Facebook users ran into trouble in the past year, everything from someone using their log-in without their permission to them being harassed or threatened.

Furthermore, Consumer Report’s investigation finds some of the personal information you widely reveal 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.
• Employers can also look for clues in wall posts and photos that may play into whether you get hired.
• The government is also peeking at your data. A 2009 IRS training manual shows how to use social networks such as 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 percent 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 cyber-bullying in the past year. Children under 13 are not supposed to use Facebook. And Facebook has closed hundreds of thousands of those accounts, according to Consumer Reports’ estimates. But it calculates more than 5 million underage children still have accounts.