When you sign up for Facebook on your phone, the app isn’t just giving you the latest updates and photos from your friends and family. In the background, it’s utilizing the phone’s gyroscope to detect subtle movements that come from breathing. It’s measuring how quickly you tap on the screen, and even looking at what angle the phone is being held.

Sound creepy? These are just some of the ways that Facebook is verifying that you’re actually human and not one of the tens of millions of bots attempting to invade the social network each day.