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