[{'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: AGE RESTRICTIONS Children under the age of 13 are not allowed to use WeChat. We do not knowingly collect Personal Information from any children under the age of 13. Please contact our Privacy Officer if you believe we have any Personal Information from any children under the age of 13 - we will promptly investigate (and remove) such Personal Information."}, {'role': 'assistant', 'content': 'This clause is fair. The privacy practices mentioned are: nan.'}]