Back in 2014, Facebook acquired messaging service WhatsApp in a headline-grabbing $16 billion deal. WhatsApp, though, had been built around respecting users’ privacy, while Facebook is, well, the exact opposite of that.

Then, and for two years after, the head of WhatsApp promised that the company wasn’t going to “sell users out,” writing at the time that, “Respect for your privacy is coded into our DNA” and that he wouldn’t have sold the company to Facebook if Zuck’s empire said it wanted to change that. And to be fair, at the time Facebook stayed hands off.

But now, two years after the acquisition, Facebook is going to make all that sweet sweet data worth the price it paid for it. And it’s no small amount of data: WhatsApp cleared the billion-user mark more than six months ago.

In a blog post today, WhatsApp announced the first change to its privacy policy since before the 2014 acquisition. And while that update still keeps the contents of your messages private (and encrypted!), some other data is about to be less so.

A section about the “Facebook family of companies” has now been added to the privacy policy under the header, “How we use information.” That section reads:

“We communicate with you about our Services and features and let you know about our terms and policies and other important updates. We may provide you marketing for our Services and those of the Facebook family of companies, of which we are now a part.”

Another section, called “Affiliated Companies,” makes the connection explicitly clear:

“As part of the Facebook family of companies, WhatsApp receives information from, and shares information with, this family of companies. We may use the information we receive from them, and they may use the information we share with them, to help operate, provide, improve, understand, customize, support, and market our Services and their offerings. This includes helping improve infrastructure and delivery systems, understanding how our Services or theirs are used, securing systems, and fighting spam, abuse, or infringement activities. Facebook and the other companies in the Facebook family also may use information from us to improve your experiences within their services such as making product suggestions (for example, of friends or connections, or of interesting content) and showing relevant offers and ads.”

Translated back into English from legalese, this means that basically, your WhatsApp user data and your Facebook user data will now be linked through your phone number, which is a consistent and unique way to identify you.

Your Facebook data and WhatsApp use will be tied together to form as full a demographic picture of you as Facebook can make. So going forward, you may see friend suggestions in Facebook based on your WhatsApp contacts. You may see ads on Facebook, and around the internet, based on your WhatsApp contacts. You may (will) see your Facebook ad preferences get updated based on your WhatsApp data.

And so on and so forth into the future, in whatever use of “operate, provide, improve, understand, customize, support, and market” Facebook sees fit.

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