Enabling the Contact Sync feature in the official Facebook iPhone and iPod touch application actually uploads all of a user’s contact info from the device to Facebook, a report in The Guardian reveals. Once the sync option is enabled, all of the contacts stored on the iPhone or iPod touch are uploaded to Facebook along with their names, e-mail address and phone numbers. This information is stored in the user’s Facebook Phonebook and linked to each contact’s Facebook account based on their matching e-mail addresses or phone numbers. Linked accounts are not limited to the user’s friends, however; non-friends are included and even users who have hidden their Facebook profiles from normal searches will appear linked in this view if they have listed a phone number or e-mail address on their profile. Contact information on non-Facebook users is also stored in the phonebook with the option to invite those friends to join Facebook.