WhatsApp announced Thursday an update to its terms and privacy policy in which it will start sharing certain user data with Facebook, its parent company.  One of the uses of such data would be for ad-targeting on Facebook.

“By coordinating more with Facebook, we’ll be able to do things like track basic metrics about how often people use our services and better fight spam on WhatsApp. And by connecting your phone number with Facebook’s systems, Facebook can offer better friend suggestions and show you more relevant ads if you have an account with them. For example, you might see an ad from a company you already work with, rather than one from someone you’ve never heard of.”

This certainly goes against WhatsApp’s earlier assertion regarding its commitment to privacy.

“We plan to share some information with Facebook and the Facebook family of companies that will allow us to coordinate more, such as to fight spam and abuse, and improve experiences across our services and those of Facebook and the Facebook family. For example, once you have accepted our updated Terms and Privacy Policy, we will share some of your account information with Facebook and the Facebook family of companies, like the phone number you verified when you registered with WhatsApp, as well as the last time you used our service.”

You Can Opt Out

There are two methods of opting out of WhatsApp sharing your number with Facebook. The first has to be done before you accept the messaging app’s new terms of service. Rather than clicking “agree,” press the smaller “read more” option below, and uncheck the box that reads “Share my WhatsApp account information with Facebook…”

Even if you have already opted in, you still have 30 days to opt out.