 Thanks...
I think I know a way that EBAY does this. I think they plant images in their listings. Either beacons or well known icons.
Then, when you search and grab ads from EBAY, even if you aren't logged in, they are linking these icons to you.
If they get linked to a fixed IP address that belongs to a suspended account, and you later post them from a different account, the link is made.
I think that is how I got caught. I was stealing existing EBAY ads for my listings.
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