Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
any personal data obtained from children and parents during contests will be kept until the contest ends and prizes are delivered , and then it will be deleted . 

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