Newly developed source code from GitHub allows people to compile a profile of their friends’ sleeping habits based on their Facebook usage, as reported by Fast Company.

The code was created by Danish software developer Søren Louv-Jansen after conceptualizing just what was possible to extract from the seemingly insignificant data trails we all leave when interacting with social media sites. “By creating a simple service that checks Facebook every 10 minutes, I’m able to get an accurate picture of my friends’ Facebook usage,” Louv-Jansen wrote on Medium. “Many people visit Facebook as the first thing in the morning, and the last thing before going to bed. It is therefore possible to get a good impression of their sleeping habits (or lack thereof).”

Specifically, Louv-Jansen says the data he scrapes which he then compiles into an estimate of a friend’s sleeping habits comes from the web-based Messenger tool that Facebook offers that allows people to chat online. That tool logs when a user was last active on the site. Louv-Jansen says he didn’t create the code just because he could. Louv-Jansen told the Washington Post he did it to demonstrate how important online privacy is and because he wants people to “be aware that they’re leaving some digital footsteps everywhere they go.”

View the full story at www.fastcompany.com