[…] Go ahead and see how many messages in your chats have locations attached. I’m guessing it’s a lot of them. 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.

Dismayingly, this location-based service on the part of the Messenger app is the product of a default setting, so untold numbers of users may not be aware that their whereabouts are automatically charted. What’s more, notes Khanna, the automatic setup enables people to monitor the movements of friends and acquaintances.

Gawker posted a follow-on to Khanna’s initial report Thursday:

Khanna updated his post to say that Facebook has notified him that “they are fixing this issue”— but that’s a fundamental, naive misunderstanding of how the site works. This wasn’t an “issue” that required a “fix” until someone pointed out how uncomfortable and sinister it is that a corporation had lured us into providing them with this level of personal information. Facebook Messenger didn’t just erupt, spontaneously, from some primordial code bog; it was designed some of the smartest and most deliberate engineers in the world. If it’s creepy, it’s creepy on purpose.

And that is how the quaint notion of privacy goes the way of the dodo, one instant message at a time.