Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
some content may contain `` r-rated '' material , nudity , profanity , and mature subject matter . 

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