Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
account security : you are responsible for all activity that occurs under your account , including any activity by authorized or unauthorized users . 

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