Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
we reserve the right , but not the obligation , to monitor or become involved in disputes between you and other users . 

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