Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
if any online activity offered by us will allow children under the age of thirteen ( 13 ) to reveal personal data publicly ( for example via un-moderated forums ) , we will obtain parental consent before allowing the child to participate . 

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