Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
the transfer of virtual items and merchandise is prohibited except where expressly authorized in the service . 

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