[{'role': 'user', 'content': 'Analyze the following clause from a privacy policy and determine if it\'s fair or unfair. Also identify any privacy practices mentioned: Address Book If you are not already a user of the Service, when you first install an application that is part of the Service on your device, you are invited to register with Tango and as part of this initial registration, you will be asked to allow us access to your address book. If you consent, we will have access to contact information in your address book on the devices you use for the Service (names, numbers, emails, and Facebook ID, but not notes or other personally identifiable information) and we will store it on our servers and use it to improve the Service and help you use the Service. If you do not want Tango to store this information, you may opt-out at any time through your account settings in the Tango mobile app, or in your deviceâ€™s privacy settings, in which case we will delete that information from our servers. However, in this case, we may not be able to offer some of the features that require this information. See also â€œHow We Use the Information We Collect" below.'}, {'role': 'assistant', 'content': 'This clause is unfair. The privacy practices mentioned are: Contact_1stParty, Contact_Address_Book_1stParty, Contact_E_Mail_Address_1stParty, Contact_Phone_Number_1stParty.'}]