Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
it is fitbit 's policy , in appropriate circumstances and at our discretion , to disable or terminate the accounts of users who repeatedly infringe the rights of copyright holders . 

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