Ebay has been the bulk of my experience with this, and they deal with it *VERY* poorly.
MicroSDXC card which is labelled as 32GB but actually rewrites sectors at about 4GB (you won't know until after you used it awhile), ah well they sold that to you too long ago so we won't deal with it, even though it's fraud
DVD series that's boxed nicely but obviously not legit (poor subtitles taken from fansubs, even some eps with scan-lines)... well we'll do something about that *IF* you can prove they're fake by having a professional sign off on it.
Seems China is doing more about it than anyone here. The above are pretty well known issues once you start looking into things, but no charges of "profiting from the proceeds of crime" hitting eBay that I've ever heard of.