These popular apps tell Facebook your weight, blood pressure, and even ovulation cycle

You don't have to have a Facebook account for Facebook to know all about you.

In its testing of more than 70 of the most popular apps in Apple's iOS store,The Wall Street Journal has found that at least 11 of them collected personal data and sent it to Facebook. Users didn't even have to be logged into the apps via Facebook, or even have a Facebook account, for their data to be shipped out, the Journal reports.

Most apps warn users that their data may be sent to third parties, but usually don't specify who. Reports have also shown that Facebook gets data regarding when users open other apps. But in the case of several top apps, personal and sensitive data was set to Facebook — some "immediately after it was collected," the Journal says. Those apps include Realtor.com, which told Facebook when users liked certain real estate properties, and Heart Rate:HR Monitor, which shared a user's heart rate.

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

One of the most disturbing findings came from Flo Period & Ovulation Tracker, which says it has 25 million active users. It told "Facebook when a user was having her period or informed the app of an intention to get pregnant," the Journal reports via its testing. In a statement, Flo said it only sends Facebook "depersonalized" information, but the Journal found there was a "unique advertising identifier" linked to the data. A Flo spokesperson then said the app would "substantially limit" its external analytics tracking and run a privacy audit.

A Facebook spokeswoman said it tells apps not to send personal data, tells them to "be clear" about what information they collect from users, and will crack down further on violators. The Journal tested the apps using "software to monitor the internet communications triggered by using an app," it writes. Online privacy company Disconnect repeated the Journal's testing and confirmed its results. Read The Wall Street Journal's whole report here.