If You are not happy about that, you have two choices. You can either stop using Whats App entirely or simply you can opt out this message.
How can you opt out?
In brief: While launching WhatsApp, you’ll see an updated Terms of Service. At the bottom of the screen, there’s a checkbox. Uncheck the box, then tap Agree, and your data will not be shared.
If you already blindly availed the service without going through it, don’t worry, you can still opt out:
Launch WhatsApp and tap Settings.
Uncheck the box marked “Share my account info.”
In detail: If you are an existing user, you can choose not to share your account information with Facebook.
There are two ways to do this
The Facebook family of companies will still receive and use this information for other purposes such as improving infrastructure and delivery systems.
The new policy might draw flak over privacy concerns. WhatsApp had promised earlier that it will not use user information for advertising. Since its acquisition by Facebook, there were speculations that it will be a shift to a money-making policy.
WhatsApp is looking forward to strengthen its business and customer support with this change. Since it had dropped the annual subscription fee earlier, it is trying to explore new revenue opportunities.
Source : The Logical Indian