“In the mood for love, or just after a one-night stand? [This app] puts you in control! Reveal the hottest nightspots, who’s in them, and how to reach them . . .”

“Browse photos of lovely local ladies and tap their thumbnail to find out more about them.”

“[This app] is a revolutionary new city scanner app than [sic] turns your town into a dating paradise!”

--The pitch from a controversial app

Many people join online dating services. But recently, a controversial mobile app created profiles of men and women, many of whom didn’t know their information – including their location – was being shared by an app advertised as a “dating paradise” for finding “love." The app created profiles of these men and women by collecting information that was publicly available through foursquare and Facebook – like location, photos, and contact information -- and presenting it in a context that many people found surprising, and even disturbing. Users of the app were able to scan their surrounding area to view the profiles of men and women who were nearby, even though many of those men and women never signed-up to be a part of the service. 

After much negative publicity, the controversial app was shut down by its developer. But the episode has an important message for anyone who uses social media: there’s not much to stop developers from using the information you make publicly available online in ways you don’t anticipate. Still, here are a few ways to help control the flow and context of your information:  

1. Use Privacy Controls. Facebook, foursquare, and many other online services provide you with settings to limit the amount of your information that is publicly available. However, a recent survey by Consumer Reports found that 13 million Facebook users had never set, or didn’t know about, Facebook’s privacy controls. Use privacy settings to control who else on the service can view your information. Look for settings that can limit the use of your information by third parties and whether it is indexed on search engines. If a service doesn’t have privacy controls, or doesn’t provide as much control as you want, consider taking your online activities elsewhere.

2.  Be Aware of Aggregation. So you’ve set your privacy controls and you’re comfortable with how much information you’re sharing on each service you use. But are you okay with the information you’re sharing on each of those services being combined? Data aggregators search for data about you from across the internet (and sometimes from offline sources, like a local courthouse) and compile it into a format that their customers can easily access.  In a sense, the recent controversial app was a mobile data aggregator that brought together information from different services to create profiles of men and women that could be easily accessed by the app’s users.  Some data aggregators provide an opt-out so you can remove your profile from the service.  If you use a search engine to search for yourself, you can find many of the data aggregators that have profiles about you, and ask them to remove your profiles. But other data aggregators are less transparent in their practices, and may not offer an opt-out. That means that the information you make publicly available online may be compiled, used, and distributed in ways you don’t expect.

3. Remember that Sensitivity Changes with Context. The recent controversial app took information originally posted in one context, foursquare and Facebook, and placed it into another context that many people consider more sensitive, a dating service. When posting online, it’s important to recognize that certain types of information may be more sensitive in one context than in others. For example, seemingly-innocuous information, like the name of your first pet, may be information that is used by banks or other companies to authenticate your identity if you forget your password or get locked out of your account. Similarly, posting your location can be a fun way to let your friends follow your summer travels. But to a burglar, it’s a signal that you’ve left your house for an extended period. And while posting your date of birth on a social network allows family and friends to wish you a happy birthday, it’s also a valuable piece of information for identity thieves. Before making information publicly available online, think about how the information could be misused in another context, and whether you can accomplish the same goal by sharing less information. For example, do you really need to share the year you were born to receive birthday wishes, or is the month and date enough?