Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
please note : section 19 of these terms of service contains an arbitration clause and class action waiver that applies to all airbnb members . 

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