[{'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: Big Duck will occasionally update this Privacy Policy. When we do, we will also revise the "Last Update" date at the bottom of this Privacy Policy. Big Duck will obtain your opt-in consent for any updates to this Privacy Policy that materially expand any sharing or use of your PII in ways not disclosed in this Privacy Policy at the time you registered.'}, {'role': 'assistant', 'content': 'This clause is fair. The privacy practices mentioned are: nan.'}]