eBay is constantly embattled over the sale of cheap knock-offs being sold on the site. They are currently in court with Tiffany and a decision is expected in the mid December.
First, eBay is a selling platform but does not sell anything, so when people say they they got something from eBay, they most often mean they bought it from someone who sells on eBay, not actually FROM eBay.
A small technicality? Not really. eBay strives to keep their marketplace as honest and safe as possible, but it is the individual seller that should be responsible for their actions, warranties and claims.
Yesterday I received a frantic call from one of my students because eBay suspended their site due to what appears to be trademark violations. I am just getting into this, but at first blush it seems that eBay search spiders are aggressively seeking out trademark search words, then making the seller re-confirm their identity and sign an affidavit that they are not selling trademarked knock-offs.
I would bet it is in an effort to prove to the courts that they are trying hard, but I believe they could go about it a different way. The marketplace is ever changing, and I believe eBay will always strive to make it as safe as possible. I am not sure my student shares that same opinion right now, but we will get it worked out.