Gmail: Trap my contacts now (warning when exporting contacts to Facebook)
Apparently, it's just for Facebook only.<p><a href="https://www.google.com/mail/help/contacts_export_confirm.html" rel="nofollow">https://www.google.com/mail/help/contacts_export_confirm.htm...</a><p>By the link of this, one can see that only exporting to Facebook would render this confirmation message.