[{'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: Advertising data collection systems. We use them to offer advertisements that are tailored to your interests, to track displayed advertisements, including the number of clicks on each advertisement, and to track the actions of users on the pages where the advertisements are leading to."}, {'role': 'assistant', 'content': 'This clause is fair. The privacy practices mentioned are: nan.'}]