Facebook has more than a billion users, and no two of us probably use it for the exact same reasons. We all know the popular uses of Facebook: sharing photos, bragging about your kids, raving about the meal you just ate, and stalking that person you don’t actually want to talk to, but about whom you’re slightly curious.There’s a more important reason to use Facebook though: It’s a great Idiot Warning System.First, let me explain what I’m not talking about. We all have those friends with whom we disagree about certain things. I’m sure many of my Facebook friends roll their eyes or curse me when I post something that displays my liberal tree-hugger ideology. (But to be fair, as I once read in a New Yorker cartoon, it’s not the tree huggers you have to worry about, it’s the tree humpers.)And I have plenty of friends who post things that I disagree with. There are conservatives, Cardinals fans, pop music fans, and various other deviant behaviors represented on my friends list.Those are personal differences that probably only arise when discussing politics, sports or some other topics. Avoid those topics and those people are probably cool and fun to be around.The Idiot Warning System applies to a special group of people: by definition, idiots.We all have these people on our friends list. If you’ve ever read a post and your first reaction was, “What the hell?” then you know what I’m talking about.These posts are usually shared posts, as idiots love company. And even when they look like original posts, if you dig a little deeper you’ll probably discover that they’re just parroting lame-brain ideas they’ve read elsewhere.So what kind of posts should you keep an eye out for? There are several indicators that make the Idiot Warning System (IWS) so effective.The most glaring marker that is sure to set off the IWS is any post that shares information that claims to “uncover the truth” or “reveal” a secret. Most of these posts are far-out conspiracy theories written for no other reason than people will believe them and share them. Read as fiction, these posts can be entertaining. However, the people who believe them to be true definitely fall under the IWS.Another category you should look out for are the single-issue Facebook users. We all have things we’re interested in, and we’ll all post something about those interests. The IWS kicks in when those interests become obsessions. Most of the time these are political interests.Hey Mr. “Gun Rights” man, you think your right to a gun trumps every other person’s right to anything else. I get it. But no matter how many times you post something about it, and no matter how many cutesy/ dangerous/ threatening/ “patriotic” ways you post about it, you’re probably not going to convince anyone who doesn’t already agree with you. Time to broaden your horizons.I don’t know why Facebook doesn’t advertise its utility as an Idiot Warning System. It might be the most useful way that Facebook has changed our lives. Sure it’s nice to catch up with old friends, and it’s fun to peruse photos of people you barely know, and I don’t know how we ever survived without knowing what that guy we haven’t talked to since eighth grade had for dinner at the new bar and grill.But the Idiot Warning System might save our lives someday. For years the only way to root out the idiots were to get to know them, which requires a heavy investment of our time, or at least view them in close proximity, which poses a risk to our safety. However, the IWS lets us identify these people from a safe distance, with practically no time investment.Thank you Facebook.And before you send me a snarky message, I’m well aware that a segment of the population probably thinks that I’m an idiot, and maybe they’re right. But that’s why words like hide, unfriend and delete were created!So go ahead. Idiot.Like my Facebook page, Brett Baker Writes.Want an e-mail every time I write something new? Type your email address in the box and click the "create subscription" button. I'm not going to send you a bunch of junk, and you can ditch me any time you want.