Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
- signature of consumer ( s ) ( only if this form is notified on paper ) , 

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