Ever since smartphones came to be, people have been using them for all sorts location-based services. Need to find the nearest gas station? Curious about what restaurants are near your hotel while you're on vacation? Want to check-in to a coffee shop so you can get your next drink for free? Chances are, your smartphone is the best tool in your arsenal to knock out all three … and certainly much more.

As time goes on and more people adopt smartphones, developers conjure up new and clever ways to put your smartphone's GPS to use. More often than not, location-based apps are utilities that, like mentioned above, are helpful when you're on vacation or even when you're on an unfamiliar side of your own town. Others are purely social and are generally in innocent, harmless fun. The infamous Foursquare check-in, for example, pits you against your friends and turns making a trip to the grocery store into a game.

Sure, there are dangers associated with sharing your location. There's a lot of information that gets publicly shared on the Internet that most people don't give second thought to. With check-ins, you could be letting someone know you're away from home and that it might be a while before you return. Or you might be cluing people in on a routine that you may have.

And that's just it. There is a ton of shared information out there at anyone's disposal.

This past Friday, I ran across and a Cult of Mac article, This Creepy App Isn’t Just Stalking Women Without Their Knowledge, It’s A Wake-Up Call About Facebook Privacy, by John Brownlee. It was a rather lengthy article exposing and detailing an iOS application called Girls Around Me. The app is exactly what you would expect after looking at the app's splash screen, which is a couple seductively posing women figures atop a map. It is a location-based application that pulls APIs from Foursquare and Facebook to give map-plotted information and last known locations of the girls around the user.

Brownlee gives an account of showing the app to some of his friends and gives them an example of what can be found with the app. Zoe was a girl who has just checked-in to a local bar or club called the Independent that was "just around the corner."

"Most of her information is visible, so I now know her full name. I can see at a glance that she’s single, that she is 24, that she went to Stoneham High School and Bunker Hill Community College, that she likes to travel, that her favorite book is Gone With The Wind and her favorite musician is Tori Amos, and that she’s a liberal. I can see the names of her family and friends. I can see her birthday.

Okay, so it looks like Zoe is my kind of girl. From her photo albums, I can see that she likes to party, and given the number of guys she takes photos with at bars and clubs at night, I can deduce that she’s frisky when she’s drunk, and her favorite drink is a frosty margarita. She appears to have recently been in Rome. Also, since her photo album contains pictures she took at the beach, I now know what Zoe looks like in a bikini… which, as it happens, is pretty damn good.

So now I know everything to know about Zoe. I know where she is. I know what she looks like, both clothed and mostly disrobed. I know her full name, her parents’ full names, her brother’s full name. I know what she likes to drink. I know where she went to school. I know what she likes and dislikes. All I need to do now is go down to the Independent, ask her if she remembers me from Stoneham High, ask her how her brother Mike is doing, buy her a frosty margarita, and start waxing eloquently about that beautiful summer I spent in Roma."

Brownlee says that this demonstration actually put one of his friends on the verge of tears in, what we assume, were tears of both fear and shock. I imagine anyone who has publicly shared their location and other information without ever giving any sort of consideration to who might actually be able to access their information would be mortified.

Since Brownlee's article went live Friday evening, Foursquare has revoked Girls Around Me's access to their APIs and the developer, Russia-based i-Free, pulled the app from the App Store. (It was pretty useless without the Foursquare API.) Aside from a big controversy over the application itself and whether it was morally right or wrong, the bigger issue here are the privacy concerns that Girls Around Me exploited.

Sure, the information is public, whether the Facebook and Foursquare users intend for it to be or not. Morals aside, Girls Around Me, technically, wasn't doing anything wrong. But there definitely should be some safety concerns here, and Foursquare, I'm sure, wouldn't want to be liable for stalkers, date rapes and who knows what else could stem from the sketchy app.

It should be an eye-opener for everyone, one that should make think twice about what they're sharing and, more importantly, with whom.

I used to share everything I ever did on the Internet. Everywhere I went, I would check-in, tweet about it and post a couple pictures. I still tweet all the time and post pictures like a mad man. But I really started giving thought to what I was doing with checking-in to every place I ever went. Not only did it get old, but when I went back through my account and could see obvious, blatant patterns in my schedule jumping out at me through what was my publicly available Foursquare profile, I decided it was time to take a step back and share a little less of my private life online. I wasn't totally blindsided by it like Brownlee's friend and I didn't burst into tears, but I was definitely a little surprised at how easy it was just to find a pattern in my weekly routine just by looking at my profile.

I still share my location from time to time. But I only share when I'm at places I don't visit very often, like a national or amusement park, and some occasional times at the places I frequent. And I could, of course, just lock down all of my profiles like Fort Knox. However, that would very nearly defeat the purpose of being social for me.

Do applications like Girls Around Me concern you? Has it made you rethink your privacy settings on Facebook, Foursquare or your other social media accounts? I'm almost positive Girls Around Me isn't (or ... wasn't) the only app of its kind. Do you know of any other creepy apps like Girls Around Me?