Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
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the virtual items , as well as other digital content traded or exchanged for virtual items can only be used within the respective digital product , can not be transferred to a third party ( unless a transfer is permitted within the digital product ) and can not be exchanged for legal tender or any item or right outside of the digital product . 

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