With older versions of iOS (5) sync iPhone contacts with Facebook was a feature available in the app Official Facebook, with the introduction of the new operating system 6.xx Facebook has been integrated into Apple's IOS operating system. The guide to synchronize contacts between iPhone / iPad and Facebook is changed.To sync your iPhone contacts with Facebook is necessary to enter in the settings of our phone by clicking on the icon shown on the left.
Scrolling down, under the settings of native apps for iOS will find the voice Twitter and Facebook. Click on Facebook.
After doing this your iPhone / iPad or iPod touch will connected and linked with your Facebook account. It will be possible then sync your iPhone calendar with Facebook events, and synchronize your contacts with your Facebook friends.
In addition to this information, from this moment on, other apps can interact with your Facebook account by asking proactively consent.
On this page you can choose which settings Facebook app can access your Facebook account; for example you can choose to not synchronize the calendar, the rubria or many other applications with Facebook at any time.
The contacts present on your iPhone, if they match with friends on Facebook will automatically synchronize with the information in the social network and will be also updated the photograph visible in the directory or when you receive a call.
Pressing the button “Update all contacts” in this settings page on your Apple device, Facebook will provide email addresses and cell phone numbers of the contacts in your phone. In this way Facebook check if the contacts on your phone have a Facebook account to update the data.
This data also provides information about a Facebook users you have on your phone but which are not friends on Facebook: This allows Facebook to suggest friendships.
Quiet, these data sent to Facebook not be visible to anyone except you: you can see the history of syncs with Facebook directly on this page:
On this page there is a link to delete this information from the archives of Facebook “personal”