This technical report analyzes certain features of Facebook, including contact importing,
synchronization, and opting out of invitations. The report finds that:
1. Imported contact information, including from non-users, is stored in Facebook's systems and can be used to suggest connections or send invitations.
2. Contact data synced from mobile apps like iPhone is transmitted without encryption, but only names, emails and phone numbers are shared.
3. While an opt-out mechanism exists to stop invitation emails, opted-out non-users can still receive private messages from Facebook users.
4. The report identifies inconsistencies in how Facebook represents synchronized contact data to users.