Some of your favorite iOS apps are feeding your data to Facebook

Deleting your Facebook account isn’t enough to stop some apps from sending deeply personal information about you to the social network.

The Wall Street Journal found a wide range of apps that send personal information to Facebook even if you don’t have an account. Health apps and real estate apps were discovered sending a lot of information to Facebook and the type of data might surprise you.

After looking into 70 of the most popular apps on iOS, WSJ found 11 that sent personal information to Facebook. The news comes just weeks after Facebook was caught distributing a VPN app to teenagers that were paid to share all of their data. Apple pulled Facebook’s enterprise certifications as payback. That hasn’t stopped Facebook from sucking up as much data as possible from every source possible.

Watchout for these apps

The period-tracking app Flo Period & Ovulation Tracker reportedly shares data with Facebook like when users are having their periods or if they’re trying to get pregnant. The top heart-rate app for iOS, Instant Heart Rate sent users’ heart rates to Facebook. Another app, Realtor, sent listing information viewed by users.

Most of these apps are sending information to Facebook without any prominent disclosures to the users. The apps use Facebook’s analytics tool called App Events to track activity. Using App Events allows for more targeted ads. The information sent is usually anonymized, but some info could be matched to users.

“Sharing information across apps on your iPhone or Android device is how mobile advertising works and is industry standard practice,” Facebook said in a statement to CNBC. The issue is how apps use information for online advertising. We require app developers to be clear with their users about the information they are sharing with us, and we prohibit app developers from sending us sensitive data. We also take steps to detect and remove data that should not be shared with us.”