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