If you have used Facebook Messenger for any significant length of time, you would know already that by default, the app uses your location and shares it with everyone you are chatting with. You have to manually disable it if you do not want this to happen.
Well, a young lad (Aran Khanna) who was working as an intern at Facebook developed a Chrome extension that scrapes all this location data that Messenger shares and plots it on a map.
Here is an excerpt from his findings:
I am in a pretty active group chat with some of my brother’s friends (who I am friends with on Facebook but don’t know too well). They are all fairly active on the chat, posting once a day or more.
Let’s pick on the one who goes to Stanford. By simply looking at the cluster of messages sent late at night you can tell exactly where his dorm is, and in fact approximately where his room is located in that dorm.
Furthermore, by gathering a couple weeks’ worth of chat data on the map and looking at the location clusters you can even figure out his weekly schedule. With this you can predict exactly which building he would be in at a given time.
Like he said in his blog post, attaching a location to a single message is not a big problem, but over time the information from each and every one of those messages adds up to become a powerful tool that can be used against the person in question. I think of apps/services like Uber, Google Now and the like, and shudder should all that location info fall into the hands of criminal minds.
Anyway, as expected, Facebook had a tete-a-tete with him, asking him not to speak to the press about it. They also requested that he deactivate the extension, and lastly they also deactivated location sharing from the desktop webpage. Oh; but not so lastly, according to this post, Facebook sent him away.
Oh, well. The more things change, the more things stay the same.