(The author is a Reuters contributor.)

By Geoff Williams

(Reuters) - The old maxim goes: If you can't say anything nice, don't say anything at all. For divorcing spouses, that may actually constitute legal advice in these days where Internet and social media sites have become a significant part of many people's daily lives. Divorce is an emotionally charged topic, but letting it all out in a public forum can lead you right into court, sued for libel or having a harsher judgment levied against you in a divorce settlement.

"You give up so much privacy, and if you don't understand the consequences of it, you can really have problems," says Adam Swickle, a divorce attorney in Fort Lauderdale, Florida. "The Internet is a dangerous place to comment on your divorce."

According to a 2010 survey conducted by the American Academy of Matrimonial Lawyers, 81 percent of their members said that they had seen an increase in the number of cases using social networking evidence during the last five years. So if you use social media sites frequently, and you're in the midst of breaking up a marriage, consider the following:

1. What you write can get you sued.

"You can call someone an idiot or a jerk, and you're okay because it's your opinion," Swickle says. "We have freedom of speech in this country. Even if it affects your reputation, if it's the truth, you can't sue for it."

But where you might get in trouble is if you lie, warns Swickle. For instance, if you call your ex a deadbeat dad who is behind on his child support payments, or an abusive alcoholic, and none of this is true - and he or she can prove it isn't true - then you could be successfully sued for libel. But those cases are rare because they're hard to prove, says Swickle.

It's also hard to prove that a barrage of Facebook or blog posts are, say, harassment or even a form of Internet stalking, says Jacqueline Newman, the managing partner at a New York City matrimonial and divorce law firm. She says that you'd have to show evidence of damages.

But she recommends that if you have an ex who is going off the deep end, ask your lawyer to talk to your ex's lawyer. "The hope is that the lawyer will be able to control the client and explain to the client that all of this ranting online isn't going to be beneficial to their case," says Newman.

2. Even if legal, some statements can hurt you.

Short of libel, there's still a lot of trouble that you can get into. Newman once had a client who wrote a blog post trashing her soon-to-be ex. "She said he was a liar, a cheat, a thief and couldn't be trusted," Newman says.

While it may have felt good for Newman's client to get all of that off her chest, the blog was read by her client's husband's boss. "It had a direct impact on his career which therefore had a direct impact on his financial ability to provide for her and their children in the future," says Newman. "It was a very expensive blog for both of them."

Also, those rants, missives and photographs are now often getting handed over in paper form to a grim-faced judge who is deciding which parent is the more deserving of full custody, or how much alimony should be shelled out.

"Judges don't like reading those blog posts, tweets or Facebook status updates," Newman says. "Especially if you have children. These things don't go away, and a judge will tell you that your children will learn to tweet, and they'll read what you write in the heat of the moment. It's awful. Loose fingers can be worse than loose lips."

3. Even if nothing you write is negative, it can still hurt you.

"In a divorce case, there's nothing better for the other side when you have someone claiming they have no money for spousal or child support, and yet they're talking on Facebook about the vacation they just took," Swickle says.

If you are concerned about your ex discussing you on social media, you can try to work protections into your settlement. "How much teeth that will have in litigation is another question," says Newman, "but someone might be scared enough that they don't want to find out."

During a high-profile court case, the judge also might decide on his or her own that nobody should be blabbing on social media and issue a gag order, in which neither party can talk about their case to the public. That happened earlier this year with former Dallas Cowboys star Deion Sanders when he was going through a turbulent divorce with his wife, Pilar. Deion wrote tweets relating to his divorce, which was in violation of the gag order, Pilar's attorney, Peter Schulte, argued at the time.

4. An apology may be in order.

If you've trashed an eventual ex on the Internet and regret it, these two words might rescue you: I'm sorry.

"You can't unring a bell," Swickle says, "but just like a newspaper, you can print a retraction. You can say that yesterday you were angry and what you wrote really isn't true, please ignore it. It's the smart thing to do, and it may take you out of a problem."

In fact, earlier this year, a Cincinnati-based photographer, Mark Byron, criticized his eventual ex-wife on Facebook and blocked her access so she wouldn't see it. Nevertheless, she did, and then so did a judge, who ordered Byron to post an apology to his wife for the next 30 days - or face jail.

Byron posted the apology for the next 26 days, stopping a little early after deciding his free speech was being derailed. The judge, who had been criticized in the press for trampling on Byron's free speech, disagreed with that assessment but didn't send him to jail.

(Follow us @ReutersMoney or at http://www.reuters.com/finance/personal-finance. Editing by Beth Pinsker Gladstone and Andrew Hay)

Earlier on HuffPost:

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  • Your Birth Date And Place

    While it might be nice to hear from Facebook well-wishers on your birthday, you should think twice before posting your full birthday. Beth Givens, executive director of the <a href="http://www.privacyrights.org/" target="_hplink">Privacy Rights Clearinghouse</a> <a href="http://finance.yahoo.com/family-home/article/110674/6-things-you-should-never-reveal-on-facebook">advises</a> that revealing your exact birthday and your place of birth is like handing over your financial security to thieves. Furthermore, Carnegie Mellon researchers recently <a href="http://arstechnica.com/tech-policy/news/2009/07/social-insecurity-numbers-open-to-hacking.ars" target="_hplink">discovered</a> that they could reconstruct social security numbers using an individual's birthday and place of birth. Rather than remove your birthday entirely, you could enter a date that's just a few days off from your real birthday.

  • Your Mother's Maiden Name

    "Your mother’s maiden name is an especially valuable bit of information, not least since it’s often the answer to security questions on many sites," writes the <em><a href="http://bucks.blogs.nytimes.com/2010/10/12/what-not-to-tell-facebook-friends/?src=tptw" target="_hplink">New York Times</a></em>. Credit card companies, your wireless service provider, and numerous other firms frequently rely on this tidbit to protect your personal information.

  • Your Home Address

    Publicizing your home address enables everyone and anyone with whom you've shared that information to see where you live, from exes to employers. Opening up in this way could have negative repercussions: for example, there have been instances in which <a href="http://www.huffingtonpost.com/2010/02/17/please-rob-me-site-tells_n_465966.html" target="_hplink">burglars have used Facebook to target users</a> who said they were not at home.

  • Your Long Trips Away From Home

    Don't post status updates that mention when you will be away from home, <a href="http://bucks.blogs.nytimes.com/2010/09/15/dont-tell-facebook-friends-that-youre-going-away/" target="_hplink">advises</a> <em>New York Times</em> columnist Ron Lieber. When you broadcast your vacation dates, you might be telling untrustworthy Facebook "friends" that your house is empty and unwatched. "[R]emind 'friends' that you have an alarm or a guard dog," Lieber writes.

  • Your Short Trips Away From Home

    Although new features like Facebook Places encourage you to check in during outings and broadcast your location (be it at a restaurant, park, or store), you might think twice even before sharing information about shorter departures from your home. "Don’t post messages such as 'out for a run' or 'at the mall shopping for my sweetie,'" Identity Theft 911 <a href="http://identitytheft911.com/company/press/release.ext?sp=11132" target="_hplink">cautions</a>. "Thieves could use that information to physically break in your house."

  • Your Inappropriate Photos

    By now, nearly everyone knows that racy, illicit, or otherwise incriminating photos posted on Facebook can cost you a job (or worse). But even deleted photos could come back to haunt you. Ars Technica recently <a href="http://arstechnica.com/web/news/2010/10/facebook-may-be-making-strides.ars" target="_hplink">discovered</a> that Facebook's servers can store deleted photos for an unspecified amount of time. "It's possible," a Facebook spokesperson <a href="http://arstechnica.com/web/news/2010/10/facebook-may-be-making-strides.ars" target="_hplink">told</a> Ars Technica, "that someone who previously had access to a photo and saved the direct URL from our content delivery network partner could still access the photo."

  • Confessionals

    Flubbing on your tax returns? Can't stand your boss? Pulled a 'dine and dash?' Don't tell Facebook. The site's privacy settings allow you to control with whom you share certain information--for example, you can create a Group that consists only of your closest friends--but, once posted, it can be hard to erase proof of your illicit or illegal activities, and difficult to keep it from spreading. There are countless examples of workers getting the axe for oversharing on Facebook, as well as many instances in which <a href="http://www.huffingtonpost.com/2010/08/16/arrested-over-facebook-po_n_683160.html" target="_hplink">people have been arrested</a> for information they shared on the social networking site. (Click <a href="http://www.huffingtonpost.com/2010/07/26/fired-over-facebook-posts_n_659170.html" target="_hplink">here</a> to see a few examples of Facebook posts that got people canned.)

  • Your Phone Number

    Watch where you post your phone number. Include it in your profile and, depending on your privacy settings, even your most distant Facebook "friends" (think exes, elementary school contacts, friends-of-friends) might be able to access it and give you a ring. Sharing it with Facebook Pages can also get you in trouble. Developer Tom Scott created an app called <a href="http://www.huffingtonpost.com/2010/05/24/evil-facebook-app-exposes_n_587144.html" target="_hplink">Evil</a> that displays phone numbers published anywhere on Facebook. <a href="http://www.huffingtonpost.com/2010/05/24/evil-facebook-app-exposes_n_587144.html" target="_hplink">According to Scott</a>, "There are uncountable numbers of groups on Facebook called 'lost my phone!!!!! need ur numbers!!!!!' [...] Most of them are marked as 'public', and a lot of folks don't understand what that means in Facebook's context -- to Facebook, 'public' means everyone in the world, whether they're a Facebook member or not."

  • Your Vacation Countdown

    <a href="http://finance.yahoo.com/family-home/article/110674/6-things-you-should-never-reveal-on-facebook" target="_hplink">CBSMoneyWatch.com</a> warns social network users that counting down the days to a vacation can be as negligent as stating how many days the vacation will last. "There may be a better way to say 'Rob me, please' than posting something along the lines of: 'Count-down to Maui! Two days and Ritz Carlton, here we come!' on [a social networking site]. But it's hard to think of one. Post the photos on Facebook when you return, if you like. But don't invite criminals in by telling them specifically when you'll be gone," MoneyWatch <a href="http://finance.yahoo.com/family-home/article/110674/6-things-you-should-never-reveal-on-facebook" target="_hplink">writes</a>.

  • Your Child's Name

    Identity thieves also target children. "Don't use a child's name in photo tags or captions," <a href="http://www.consumerreports.org/cro/magazine-archive/2010/june/electronics-computers/social-insecurity/7-things-to-stop-doing-on-facebook/index.htm" target="_hplink">writes</a> Consumer Reports. "If someone else does, delete it by clicking on Remove Tag. If your child isn't on Facebook and someone includes his or her name in a caption, ask that person to remove the name."

  • Your 'Risky' Behavior

    CBSMoneyWatch.com <a href="http://moneywatch.bnet.com/saving-money/blog/devil-details/6-things-you-should-never-reveal-on-facebook/2360/?tag=content;col1" target="_hplink">writes</a>: <blockquote>You take your classic Camaro out for street racing, soar above the hills in a hang glider, or smoke like a chimney? Insurers are increasingly turning to the web to figure out whether their applicants and customers are putting their lives or property at risk, according to Insure.com.</blockquote> There have been additional <a href="http://www.huffingtonpost.com/2010/02/22/facebook-twitter-users-co_n_471548.html" target="_hplink">reports</a> that insurance companies may adjust users' premiums based what they post to Facebook. Given that criminals are turning to high-tech tools like Google Street View and Facebook to target victims, "I wouldn't be surprised if, as social media grow in popularity and more location-based applications come to fore, insurance providers consider these in their pricing of an individual's risk," <a href="http://www.huffingtonpost.com/2010/02/22/facebook-twitter-users-co_n_471548.html" target="_hplink">says</a> Darren Black, head of home insurance for Confused.com.

  • The Layout Of Your Home

    <a href="http://identitytheft911.com/company/press/release.ext?sp=11132" target="_hplink">Identity Theft 911</a> reminds Facebook users never to post photos that reveal the layout of an apartment or home and the valuables therein.

  • Your Profile On Public Search

    Do you want your Facebook profile--even bare-bones information like your gender, name, and profile picture--appearing in a Google search? If not, you should should block your profile from appearing in search engine results. Consumer Reports <a href="http://www.consumerreports.org/cro/magazine-archive/2010/june/electronics-computers/social-insecurity/7-things-to-stop-doing-on-facebook/index.htm" target="_blank">advises</a> that doing so will "help prevent strangers from accessing your page." To change this privacy setting, go to Privacy Settings under Account, then Sharing on Facebook.