Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
you acknowledge and agree that you are responsible for knowing , protecting , and enforcing any intellectual property rights you hold , and that linden lab can not do so on your behalf . 

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