Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
6.1 airbnb may charge fees to hosts ( `` host fees '' ) and/or guests ( `` guest fees '' ) ( collectively , `` service fees '' ) in consideration for the use of the airbnb platform . 

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