Hold on Facebook Friends. There is a rumor going around that claims Facebook is sharing your contact list with the world, but it isn’t true.
Facebook isn’t known for having the best privacy and security practices in the business, which is why many users believed that Facebook had shared their contacts with anyone on Facebook.
In reality, Facebook Contacts are limited to viewing by you, and only you. The numbers and emails addresses stored in the Contact list comes from your contacts or from your phone.
Facebook Issued the following update to clear things up;
Rumors claiming that your phone contacts are visible to everyone on Facebook are false. Our Contacts list, formerly called Phonebook, has existed for a long time. The phone numbers listed there were either added by your friends themselves and made visible to you, or you have previously synced your phone contacts with Facebook. Just like on your phone, only you can see these numbers.
If you don’t want to sync your phone contacts to Facebook, you need to turn it off in the settings. To do this, Open the Facebook app, tap your Menu button, tap on Settings, scroll to the bottom and tap Sync Contacts. Choose Don’t Sync.
Even if you aren’t syncing contacts, you may see contact info from friends in the Facebook Contacts list as it pulls in the information other friends enter.
Why is Facebook hoping you’ll sync your contact lists and share your phone numbers? Because the company has just released a Messaging app that it hopes will replace text messaging.