It appears the only way to protect us, and you, is not to be involved. Here are some excepts from the Ebay website.
Someone's using the descriptions from my listings word for word. What can I do to stop them?
When you create a listing or product page you give eBay and its members permission, through our User Agreement, to use your images and product details. Your content may be added to the eBay product catalogue, at our discretion. Content added to the catalogue may be used by other sellers in their eBay listings.
When you upload content to the eBay website or otherwise give us content, you grant us a non-exclusive, worldwide, perpetual, irrevocable, royalty-free, sublicensable (through multiple tiers) right to exercise any and all intellectual property rights (including copyright and trademark rights you have in the content, in any media known now or in the future and for any other purpose.
If you are the author of that content, you also irrevocably and unconditionally consent, to the maximum extent permitted by law (either present or future), to eBay and its licensees, contractors, assignees and successors, and their licensees and any other person authorised by any of them (“eBay Authorised Persons”):
(a) disclosing, reproducing, copying, adapting, publishing, performing, exhibiting, communicating, renting, transmitting or otherwise using the content (and any adaptation or part of the content) anywhere in the world:
(i) in whatever form and in whatever circumstances eBay and the eBay Authorised Persons think fit, including adding to or otherwise altering the content (or any adaptation or part of the content); and
(ii) without making any identification of you as the author in relation to the content (or any adaptation or part of the content); and