If you use the popular Facebook Messenger app, the people you chat with could be stalking you. That's because the app shares your location by default and creeps could use that data to track your location throughout the day.
Harvard student Aran Khanna wanted to see just how much location data your Messenger reveals. As part of his investigation, he created a Google Chrome browser extension for the Facebook Messenger page. It collects all of the location data in your chats and plots it on a map.
And if this isn't already starting to get a bit weird, the first thing I noticed when I started to write my code was that the latitude and longitude coordinates of the message locations have more than 5 decimal places of precision, making it possible to pinpoint the sender’s location to less than a meter.
The extension made it possible for Khanna to find out the location of his brother's friend's dorm room at Stanford by using location data for chats that took place late at night. This might not seem like a huge problem if you only chat with close friends and family members. But, what about those old high school friends or former coworkers you haven't seen in ages? If you send any chat message them, they instantly have access to your exact location data, too.
It gets worse. The app could even be sharing your location data with people you don't know at all. If you're involved in a group chat with people you're not friends with, they can still access the location data attached to your messages.
Messenger only shares location data when used on a gadget with GPS on. So the easiest way to protect your location information is to simply disable the Messenger app's ability to track where you are. iOS users can do this by going into the Settings app and clicking on Privacy. Then, select Location Services and scroll down until you see Messenger. Click on Messenger and select "Never".
Android users can go into the Messenger app and tap the Settings gear in the top right corner of the screen. Then find the location setting and uncheck the box.
Facebook also contact Khanna and let him know that they are working on the problem, so hopefully you're friends won't be able to collect and map your location data for much longer.