Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
persons under the age of 13 , or the equivalent minimum age in the relevant jurisdiction , are not permitted to access or use the fitbit service unless their parent has consented in accordance with applicable law . 

```
. OPTIONS: ['Jurisdiction' 'Contract by using' 'Arbitration' 'Unilateral termination'
 'None' 'Content removal' 'Limitation of liability' 'Unilateral change'
 'Choice of law'].