Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
all purchases of digital content are final , except as required by law or as described in our mobile and rift content refund policies . 

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