Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
22.7 unless specified otherwise , any notices or other communications to members permitted or required under this agreement , will be in writing and given by airbnb via email , airbnb platform notification , or messaging service ( including sms and wechat ) . 

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