Tech, Now + Beyond

Turns out you can track your friends’ sleeping habits with Facebook, and it’s pretty creepy

You're leaving digital footprints everywhere you go, and Facebook keeps track of everything. If you're clever, so can you.

We’ve all seen the last active timestamp on Facebook’s Messenger service since it was launched.

For some, it’s concerning, and for others, it’s not bothersome. Apart from this being a feature in the Facebook Messenger app that so many of us have on our phones, the data collected can be used for other things, which in the wrong hands can be stalker-ish.

Danish software developer Soren Louv-Jansen found a way to determine his friends sleeping patterns from their Facebook activity. With Facebook and Messenger available as mobile apps in addition to the website, many of us scroll through our feed before we go to sleep or not too long after we’ve woken up.

All it took was some hacking and sleuthing to figure out what time his Facebook friends hit the hay and woke up in the morning.

He’s not alone in his curiosity about the data Facebook was collecting. Australian coder Alexander Hogues wrote a fascinating post explaining how he stumbled upon and tinkered with an undocumented Facebook API to “roleplay as the NSA,” and has shared his code on GitHub. Which makes it all the more concerning and imaginative about what else the user data Facebook collects can be used for by more determined folks.

It took Louv-Jansen six months to finish the code before it was released in December, according to a piece he wrote in the Washington Post

But it wasn’t until he published his post on Medium that it gained any attention: more than 200,000 views.

The program he wrote checked Facebook every 10 minutes. The code was also accurate for 30% of his friends and less so for the remaining 70%. For frequent users, the results are more telling. He determined that on weekdays, there were stricter sleeping patterns for his friends and on weekends that changed.

The code is available for download on GitHub. He said doesn’t plan on removing it even though he stopped using it.

The information collected is apparently in violation of Facebook’s terms of service, and he’s been asked to stop using it. But Jansen thinks it’s important for users to know that “they’re not alone, someone is always watching.”

He also said his aim was not “to spy on my friends,” but that it is an educational tool about privacy. Kinda ironic when it’s a social media website where it’s all about sharing, but only with the stuff people want to share.

Apart from annoying ads on Facebook, some of which are supposed to be tailored to our likes, what else is our data collected for?

Watch the video below to see how he discovered the sleeping patterns using Facebook activity.