WhatsApp has updated its privacy policy, and this is one its more than one billion users will want to pay attention to. In the update, WhatsApp says that it will begin sharing some information on its users with Facebook, a first for the company despite the fact that it has been owned by the social media giant for more than two years now.

In a new blog post, WhatsApp explains that it will share some users' phone numbers with Facebook, along with various metrics that could potentially help Facebook deliver more relevant ads to its registered users. While these metrics seem a little nebulous, WhatsApp says they can include the last time each individual user actually used the service.

These changes are being made in the name of decreasing spam on WhatsApp, though the company also says it wants to help users better connect with businesses that matter to them, rather than just other users. WhatsApp is also clear in saying that it won't be showing ads on the service itself, nor will it share your number with companies that don't fall under the Facebook family. The company also said that Facebook won't have access to the content of your communications.

That part about Facebook not being able to see users' content is important to note, as this privacy policy update also covers the roll out of end-to-end encryption, which is available to all users running the latest version of WhatsApp. While Facebook may be getting some information on WhatsApp's users, the company promises that end-to-end encryption means that no one else is listening in on their conversations.

Still, we can image that some WhatsApp users won't be pleased to hear that their phone numbers could end up getting shared with Facebook. WhatsApp has long been proponent of user privacy, a focus that attracted a fair few users to the service, and this will almost certainly be seen by some as WhatsApp stepping back from the strict privacy guidelines it once held.