I think we can all agree that Facebook is huge. It boasts millions of users all over the world, it's a multi-billion dollar company, it has infiltrated other sites that people use daily (if you've ever logged in to Pinterest with your FB account, you'll know what I mean), and it's free and relatively easy to use...which may be one of the scariest things about it.
If you have an account on the social media site, you've probably been a victim at one point of either spam or some random creeper trying to send you a friend request. You may have been the victim of prying eyes, as well; It's just something that goes with the online territory, unfortunately. Even the company itself isn't immune to rumors of taking a gander at our personal info; they recently got thrust into the spotlight after it was discovered that their mobile app gives them access to text messages (it's in the user policy, which you have to agree to in order to download the app).
Luckily, Facebook has amped up their privacy policies and does their best at cracking down on hackers infiltrating user information, but sometimes the bad guys aren't the ones sitting in a dark room plotting a major credit card scam in the glow of their computer screen; sometimes, the bad guys parade around right under your nose.
If you owe money to a debt collector, beware. They've apparently decided it's cool to hunt people down through Facebook and harass them--as well as their friends and family--in order to get what's owed to them. While they can only take it so far--they can't reveal online how much debt a person has accrued, for instance--there is no law that says they can't send you a friend request disguised as someone else. And don't forget about that handy check-in feature, which tells everyone who has access to your profile what your precise location is. So the lesson here is, either pay your debts or don't accept a friend request from someone you don't know...which should be a given.
Also, potential employers can look you up online before deciding whether or not they want to give you the job. Let's think about this for a minute and remember all the pictures of you--embarrassing and otherwise--that are posted on Facebook and beyond. Were you tagged at Jessica's drunken pool party last summer? Filmed doing the "cinnamon test" with your buddies on a boring Friday night? The person who holds your career fate in their hands can see all that and more, whether because your page is set to public view or because they've caught on to the debt collector scam and have infiltrated your friends' list unknowingly.
Of course, if you're careful about what you post and about who sees it, none of this matters. But the whole point of social media is to connect with others, so most of us will keep putting our lives up into that little text box the way we've been doing for years. Just don't, you know, post that photo of yourself dressed as Baby New Year guzzling two tallboy PBR's.