[{'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: Third-Party Ad Serving and Audience and Traffic Measurement Services: We may use third-parties to serve advertisements on the Services. These third parties may set their own cookies or similar web technologies to collect information about users' online activities over time and across different websites. To manage your preferences you may opt out here http://preferences-mgr.truste.com/."}, {'role': 'assistant', 'content': 'This clause is unfair. The privacy practices mentioned are: Identifier_Cookie_or_similar_Tech_3rdParty.'}]