Although eBay have rules against the listing of items which infringe copyright and are on recordable media they have hundreds of such items for sale at any one time.
Now I understand that some items can slip through the net, but there is no excuse when there are so many items that are obviously not the genuine article.
Take the case of repair manuals for cars, motorcycles, boat engines and the like. All you have to do is search for something like "MANUAL CD" and you will see hundreds (perhaps thousands) of listings for these type of repair manuals. I would suggest that most people who see these manuals realise that they are obviously either pirated copies of printed manuals or manufacturer's service data that is usually only available to dealers. Many of the advertisers even openly mention the publisher's name. I have no doubt eBay have a department full of people trained to spot listing violations such as these, but they don't appear to be doing anything about the problem, despite myself (and I'm sure many others) reporting these listings frequently in an attempt to bring this to their attention.
I guess this type of theft does not receive the same public attention as software, music and movie piracy so eBay are probably happy not to have to "waste" their resources clamping down on it, and no doubt also happy to pocket the listing and various other fees they receive for selling these stolen goods.
C'mon eBay, when are you going to something about this?
