Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
we may modify or discontinue virtual items or in-game currency at any time . 

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