According to a press release made by whatsapp this data sharing will be used only for the purpose of relevant ads and improve user experience.
…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 – WhatsApp
If you don’t want to share your contact details and information with Facebook, you can follow the simple details mentioned below.
Prevent Whatsapp sharing contacts
Here is how to prevent sharing your information (contacts) with Facebook, Opt out method.
• Launch whatsapp on your device (smartphone, tablet)
• Tap on Menu and Go to the settings tab
• Tap on account option
The last option in account menu is “Share my account information”. Tap to disable it if you don’t want to share your contacts information of whatsapp with Facebook.
Now you have to confirm it to be opt out. The section of the account will be gray out.
Whatsapp Facebook Problem solved…!
if you have followed the above mentioned steps correctly. You have successfully opted out of sharing your whatsapp account info with Facebook which they intend for the purpose of advertisement and other services..
Whatsapp existing users still have few more days to agree or not agree with the latest privacy updates. If you have already checked the agree button, you can opt out of “share my account information” from the account settings menu.
However Facebook is still having an access to your information which will they use for improving their security services and fighting against spam.