WhatsApp will now share your phone number with Facebook, even if you are using a separate number for it, in order to
"enable more targeted advertising" and fight spam. If both services are installed on the same device, Facebook will be able to pull up any phone numbers associated with WhatsApp through the device identifier. WhatsApp's privacy policy was updated with the new statement earlier on Thursday.
"For example, if someone is using Facebook in abusive fashion, sending malicious links to users and we are able to identify that account also on WhatsApp, we can disable that account and its services rather than just on Facebook," a WhatsApp rep told The Economic Times in an interview.
The new update will also positively affect Facebook's Custom Audience ad platform for businesses, by displaying more
"relevant ads" by pulling data for different phone numbers associated with the two services.
"For example, if you sign up to your local flower shop's mailing list using the same mobile phone number that you use for your WhatsApp account, and they decide to advertise on Facebook, you may see their ads on Facebook," the WhatsApp rep explained.
Thankfully, users will be able to opt out of sharing information with Facebook
"for any sort of products or ad experiences", although their phone numbers will still be shared between both services. While WhatsApp stresses that it won't
"post or share your WhatsApp number with others, including on Facebook, and […] won't sell, share, or give your number to advertisers", the privacy policy change will result in WhatsApp contacts appearing as friend suggestions on Facebook.
This is the first privacy policy change that WhatsApp has made since its acquisition by Facebook in 2014. WhatsApp users will begin receiving updates of the policy changes Thursday evening, as the changes come into effect worldwide in the following days.
Things that are NOT allowed: