You may not realize it, but the apps on your smartphone may be collecting a lot of really personal data about you.
(Read more: Facebook's next target is your cursor )
Whether it's a recommendation, dating or other social app, companies are increasingly using machine-based learning to get to know users better so that they can provide an improved user experience and target ads more effectively.
But in order to do this, users must hand over access to other personal accounts, like Facebook or email.
And while many people are happy to give access to such accounts to reap the benefits of personalization, they probably don't realize just how much personal data they are actually sharing, and that can be dangerous, experts say.
(Read more: Why Online Privacy Is a Big Oxymoron)
"People should be very concerned about this, but it's a catch 22," said Mikael Berner, CEO of EasilyDo, a smart assistant application.
"There's no way we are going to survive these days without some automation tools, so people just get used to giving their information away, but they should be thinking about what data they are putting out there, starting with their social data."
Facebook also measures a user's behavior to determine how it ranks news in a user's newsfeed. The social network looks at not only who users are engaging with, but also what pages they interact with, how long a user scrolls through their newsfeed and how much time they spend on different pages to adjust their algos to display better content in the newsfeed.