One more time: Don't be a dummy on Facebook

If we've said it once, we've said it a hundred (OK, maybe three or four) times: Don't put stuff on Facebook or any other social-networking site that can come back to bite you.

The latest proof of how damaging this can be: An Associated Press story related how divorce attorneys are routinely looking for incriminating stuff on social-networking sites, and they're finding lots of it -- most often on Facebook. "The American Academy of Matrimonial Lawyers says 81% of its members have used or faced evidence plucked from Facebook, MySpace, Twitter and other social networking sites, including YouTube and LinkedIn, over the last five years," the story says.

Evidence of cheating is a no-brainer. But people also thoughtlessly post about activities that counter their claims in court ("I don't drink." "I don't do drugs.") or support the other side's contentions. An example from the story: "Husband goes on Match.com and declares his single, childless status while seeking primary custody of said nonexistent children." The judge will love reading that.

Our warning about preserving your privacy goes far beyond divorce court.

Consider that insurance companies will likely have the technology in a few years to match current and prospective customers with their social-networking accounts. Depending on your state, posted information could be used to decide whether you will be insured or to set your rate, Marilyn Lewis reported at Insure.com.

Sound farfetched? Not really, when you consider that a woman on disability for depression lost her coverage after she posted photos of herself having good times, including at Chippendales, our buddy Marilyn said.

• Bing: Facebook blunders

Another pal, Kathy Kristof, recently provided a list of six things NEVER to share on Facebook and similar sites -- and dang good reasons why you shouldn't -- in a post at CBS MoneyWatch. Here they are, briefly:

• Birth date and place. That seems obvious, particularly when you consider that you're required to give that information when you do official things like renew your passport.
• Vacation plans. Again, obvious, or at least you'd think so. (But then, tell that to the people who have posted about their extramarital affairs.) Kathy advises that you wait until you're home to share the pictures.
• Home address. Screamingly obvious. Yet, about 40% of people do share this information.
• Stuff that can get you fired. A new study found that 8% of large companies have fired employees for behavior displayed on social-networking sites, Mashable said. Don't badmouth the boss, share company secrets or confess to doing ridiculous things.

• Video: Employees paid big cash incentives for good behavior

• Clues to your passwords. Think of the kinds of security questions you're asked when you set up an online account: favorite cousin, favorite roommate, name of first boy/girl you kissed. Just like your date and place of birth, sharing it is an invitation to identity theft.
• Risky behaviors. Note the information about the prying eyes of insurance companies above.

The AP story advises people to be aware of their privacy settings and use them. Better yet, it also suggests there are some things that you should keep to yourself or limit to very private conversations with people you trust.

More from MSN Money:

• Home seller made more, thanks to Facebook
• Facebook CEO's privacy meltdown
• Is it OK to Facebook friends for money?
• Many social-media users post risky info
• Want to lose friends and influence no one?
• How Facebook can hurt your finances