Developer creates a Facebook stalker’s greatest tool…

If you needed another reason to make sure your location sharing feature on Facebook is turned off on your mobile phone (the last one being that it was part of our 4 ways how Facebook can get you into trouble) then the Marauders Map should provide a sufficient excuse.

Many will realise that when they send a message through Facebook, if location sharing is turned on (which it is by default) then their approximate location gets pinned to the bottom of their message through some little disclaimer type text underneath stating “Sent from [location]”. (see below.)

But not many realise that every single message they send comes equipped with this little location marker, and it isn’t approximate at all. In fact after a little digging, someone could discover your location when you sent each message accurate to only a few metres!

In fact, since every message you send reveals your location, one could potentially build a history of your movements throughout recent time. Well, as it turns out, someone made such a feat quite easy, via an extension for the Chrome browser that they dubbed Marauders Map (nod to the Harry Potter films). But another unofficial name has been given to it as well, a stalkers dream.

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With the extension, you could take any of your Facebook friends and find out where they are, each time you spoke to them on Facebook or even when they commented on a thread that you could see. In fact the Facebook user doesn’t even have to be your friend, just someone who is commented on the same thread as you are.

If you have location sharing turned on when using Facebook on mobile, your GPS co-ordinates are being sent along with each message. To the average recipient, it just gives you the town name that it was sent from. But if the recipient wanted to do a little more digging, the exact GPS location is available as well.

Marauders Map essentially does all that digging, not just from the last message sent, but from all messages sent, in order of time, allowing someone to build a chronological history of a person’s movements.

The Chrome extension at work, which can plot where you have been and even to predict weekly routines

The extension was developed by Aran Khanna, who said in an interview –

Everyone I have shown this extension to has been anywhere from surprised to appalled that this much of their very personal data is online for their friends (and even complete strangers) to access. So it is seems that there is an issue.

It proves to be yet another case of how our privacy has been eroded at the behest of social media. Would we have accepted such a breach of privacy 20 years ago? Would this has been bigger news back then if it has been accomplished through 90s technology?

At the time of writing, Facebook have made no comment, but Marauders Map no longer works since the platform it was developed on pulled the plug after its popularity exploded. The code is open source though, so expect an adapted version hitting an app store near you soon.

Will this persuade you to disable location sharing on your phone? iOS users can disable it via their main Settings | Privacy menu and disable location services (which will work on all Apps) and Android users need to go into the Facebook App itself and go to Settings and turn off Location (or the “New messages include your location by default” option.)