You had a great vacation this year in Brazil, and you posted a daily journal on Facebook and tweeted regularly so your friends and family could follow your adventures. But you may have other avid readers you’re unaware of: insurance company representatives.

Insurance companies have long followed clients on social media to combat what they say is a multibillion problem of fraud. One insurance services company, Contego Services Group, has whole unit dedicated to social media investigations. "More and more are using it and they are using it more often because it works,” says James Quiggle, director of communications for the nonprofit Coalition Against Insurance Fraud.

For instance, if you check “no pets” on your  renters’ insurance policy and your Facebook page has post after post of your pooch, don’t be surprised to get a call from your insurance rep.

But now insurance reps and others may be scouring your Facebook, Twitter, Instagram and Flickr accounts and others for another reason: to see if you’re a coverage risk.

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Spying on risky behavior 

In a field once dominated by enterprising insurance investigators, insurance companies are relying more and more on data brokers and sophisticated software to scour social media and identify potential risks posed by their customers’ behavior, whether it’s a penchant for skydiving or photos that suggest a declared nonsmoker likes to light up now and then. In some cases, these programs provide social media scores to assign a level of risk to your coverage. 

Remember the fun you had zip-lining through the jungle or paragliding off the cliff in Rio? If you go to buy a life insurance policy in the future, experts say, don’t be surprised if the cost seems unusually steep.

Joe Ridout, manager of consumer services for the San Francisco-based nonprofit Consumer Action, says he has no problem with insurance companies using social media to investigate potential fraud. But it’s “outrageous,” he says, when these same sources are used as an underwriting tool.

“It’s an outrageous intrusion and can open the door to irrational bias and discrimination against a policyholder. There does not exist some actuarial hocus pocus that could distill photos or frivolous comments to actuarial risks. It looks like a smoke screen to gouge consumers.”

Related: How to Complain on Social Media Without Getting Sued (or Worse)

Not looking depressed enough for depression coverage?

Social media pics can be deceiving. The Canadian-based insurance company Manulife said it used Facebook to spy on 29-year-old Nathalie Blanchard, who was receiving benefits while she was on leave from work for major depression. Her benefits were cut off suddenly, and when she called her insurance agent, he said it was because she posted pictures of herself on a beach and also smiling at a bar on her birthday. Even though she explained that her doctor had suggested outings to take her mind off her problems, the company balked at reinstating her benefits.

Using data brokers and algorithms to gather, track and analyze client behavior online has left industry ahead of regulations. In 2014 the Federal Trade Commission issued a report on social media data brokers that found they operated with a “ fundamental lack of transparency.” The FTC called on Congress to consider legislation to give consumers greater control over the personal information data brokers collect and share.

Bottom line: Ponder before you post 

In the meantime, remember that what you and your friends post online may be seen by other eyes. To protect yourself, consumer advocates suggest taking a few basic steps. These include:

Be careful about what you post. Don't post anything that could haunt you later. Never post information relating to an open insurance claim.

Review your privacy settings. Limit access to your posts to your followers. This won’t prevent all data mining — Blanchard, for example, had set her Facebook account to the highest level of privacy — but it will offer some protection. “It’s always good,” says Consumer Action’s Ridout, “to revisit your privacy settings and make sure you are not sharing too broadly.”

Don’t broadcast your travel schedule. “If you’re robbed while you’re gone but posted trip details on Facebook or shared photos of you lounging on the beach while still on vacation, could your claim be denied? Some companies might argue that it’s similar to leaving your doors unlocked,” writes insurance reporter Desiree Baughman.

Turn off geotagging. This common feature lets friends know where you are, but it may provide information about your personal life to insurers that you’d rather not share.

Ask friends to untag or delete. Sometimes friends may identify you in photos you’d rather not have on Facebook, like one that shows you with a lampshade on your head and a beer in your hand. Your privacy settings won’t limit who sees these. Ask friends to remove the tag or photos.

Be honest with insurers. When you fill out insurance forms or file a claim, be truthful. That will take care of lots of future social media problems right there.

Related: Is It Safe to Share Photos of Your Kids Online?

Daniel S. Levine is an award-winning journalist who heads the Levine Media Group and hosts The Bio Report and RARECast podcasts. He was an editor of The Burrill Report and worked for the Oakland Tribune, Adweek, the San Francisco Business Times and other publications.