Response from Amazon:
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In order to ensure that we only remove the sellers and titles that you are completely sure are infringing your rights, we need you to provide following additional information:
1. A list of every third party seller separately for each title that you truly believe has illegally manufactured, re-copied, or otherwise unlawfully obtained your copyrighted material;
2. A statement by you that you have a good-faith belief that the disputed use is not authorized by the copyright owner, its agent, or the law;
3. A statement by you, made under penalty of perjury, that the above information in your notice is accurate and that you are the copyright owner or authorized to act on the copyright owner's behalf.
We do not need you to provide an additional signature as long as you send the above information from this e-mail address.
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We'll see what happens next.