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 . 

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