Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
contact another member for any purpose other than asking a question related to a your own booking , listing , or the member 's use of the airbnb platform , including , but not limited to , recruiting or otherwise soliciting any member to join third-party services , applications or websites , without our prior written approval ; 

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