Hyper-popular messaging app WhatsApp announced yesterday that it would start sharing some user data — including your phone number — with parent company Facebook. The two companies say the new policy will help you find friends and "improve your Facebook ads and products experiences," but it will also give businesses a new avenue to reach potential customers, with WhatsApp describing situations where banks and airlines will use your phone number to get in touch about fraudulent payments or delayed flights.

WhatsApp has promised that it won't sell or share that number with advertisers, but if you still balk at the idea of putting your phone number where a legion of hungry brands could potentially see it, you're in luck — you've still got a chance to stop WhatsApp from handing Facebook this new data if you act fast. There are two methods, as Motherboard notes, but the first has to be done before you accept the messaging app's new terms of service. Rather than clicking "agree" blindly, press the smaller "read more" option below, and uncheck the box that reads "Share my WhatsApp account information with Facebook..."

Don't worry if you've already accepted those new terms, however — you've still got 30 days to opt out. Head to the app's settings menu, and then press the account tab. From there, you can uncheck the box reading "Share my account info" to stop providing Facebook with your user data.

How Facebook decides what’s trending