Ebay sellers that make their shipping free but send things that are not magazines or books as media mail because its cheaper. The post office opens up packages and turns it into COD!
In fairness, this could be unintentional. I have been selling for awhile now and only found out about that a couple of weeks ago. I can't tell you how many toys I have received that were shipped media mail. I always assumed it was just a "class" of mail like 3rd class, 4th class, etc. I never knew you were actually restricted to only sending printed materials like this.
The guy at the PO told mke there has been a surge in the abuse of this shipping method, so they have started actively scanning/X-raying packages to verify the contents. I don't see why they wouldn't just return to sender in that scenario though. Why pass the expense on to someone who was blameless to begin with?
I send everything parcel post now, it's more expensive but less risky.
RE: categories, I have seen some threads over at RS ranting about this but didn't care to read the particulars. What exactly did they change? The Clone Wars category seems the same. To me this doesn't seem like a big deal because searching by category is a very inefficient method and I don't think most buyers do that. You're much better off searching on the specific item name.
Maybe some people just like to browse though, I don't know. My ebaying is always very target-specific.