Worst cases

You post a photo of yourself on MySpace vacationing in Europe and enjoying a glass of local wine. A week later, you lose your job, lose your insurance, lose your house, and end up living in a cardboard box under a bridge.

It could happen!

Well, at least the part about losing your job or insurance could happen—and already has, more than once. An increasing number of employers are checking up on employees and job applicants on common social networking sites, and that seemingly innocuous vacation picture may land you in the unemployment line.

Protect yourself: Understand the security controls on your site of choice and carefully manage images tagged with your name.

You're on vacation with a friend. She's a shutterbug, and snaps photos of you in front of famous landmarks to post through Facebook Places. When you get home, your house has been cleaned down to the studs.

Well, maybe...

This one requires certain stars to align. If you've posted your home address on Facebook (or your landline phone number—a reverse lookup turns that into a name and home address) and your friend likes to friend awfully shady people and said friend bothered to tag you in the photo... you get the idea.

Protect yourself: Be aware of what information is publicly available on your profile and how that information can be used to dig deeper using public records. Assume that things posted by your friends are available to the public. Oh, and hire a housesitter.

Your teenaged daughter confirms anyone who bothers to send a friend request. Her eventual disappearance ends up on national news when word gets out that she was enticed into a prop plane and flown to Cancun by a sixty-year-old man she'd only ever met on Facebook.

OK, that's paranoid.

Somewhat foolish Internet behaviors do not a complete idiot make, and predators are still rare despite news aggregators implying otherwise. There are risks in having what amounts to an open account while maintaining a false sense of exclusivity, but this extreme result is unlikely to be one of them.

Protect yourself: Standard parenting applies! Encourage your kids to manage their friends list and tell them not to broadcast home addresses or phone numbers. Prepare for much eye-rolling.

You join a social networking site. Suddenly you can't move for advertising—spam in your inbox, fliers stuck in your door, "slap the monkey" ads climbing out of your monitor to spill out onto the floor. You start to wear your shirt collars turned up and you swear you saw an ad executive peering through your bathroom window two days ago.

It could happen!—but does it matter?

It's been said that on the Internet, you are the product—your browsing habits, purchases, and eyeballs are what you trade for free access to the sites you visit. So what? Benefits are many (free ad-supported sites and apps, promotions, coupons) as are the detriments (your information being sold and shared without your input, creepy targeted ads, scams), and you must decide for yourself what the tradeoff will be.

Protect yourself: Educate yourself about how advertisers acquire and use your information. Don't post information that you don't wish to share with advertisers, including in "protected" areas of sites or even on your smartphone. (Often it will still be shared with "partners," an ambiguous term that generally means anyone with deep pockets and a pulse.) Avoid scams that purport to protect your information—sometimes these are worse than the advertisers themselves!

—Rebecca Mazur, Kenyon Web programmer