[{'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: Once the user's contractual agreement with Wooga has come to an end, essential data will be blocked for an appropriate processing period, and any optional information other than that will be erased."}, {'role': 'assistant', 'content': 'This clause is fair. The privacy practices mentioned are: nan.'}]