The difference is that Sony send threatening letters to ebay if they see PSPs with custom firmwares advertised for sale. Unless a publisher starts threatening ebay, these kind of things will probably be left alone. I know I reported this one when it was originally posted, but its still there.
These types of auction rarely last until completion, and if they do, there's nothing to stop eBay stopping the sale, refunding Paypal etc. In years gone by you *could* buy a set of MAME ROM's on eBay if you were that way inclined. Nowadays, any mention of certain keywords (the ones that people would use to find you) flags you. They have until the end of the auction date to terminate, don't forget. And now it looks like it's been pulled, so I can't see what it was for. I wouldn't be surprised if "gp2x" was on their list of keywords to check, though. You can be certain that "MAME", "rom", etc. are and if enough of them hit an auction it'll be checked manually.
I had some auctions of Windows 98 license keys pulled despite there being *no* restrictions on their re-sale under the EULA so long as they were complete with the disks etc. It wasn't even a Microsoft complaint - eBay took it upon themselves to terminate the auctions pre-emptively. You have little to no recourse under that sort of circumstance because of the EULA that eBay have, but I did get my listing fees back.
Of course, eBay HAVE to do this. It's too much legal trouble for them not to, even if the people who own the copyrights etc. don't complain. But you can't *stop* people posting the auctions in the first place (unless you want to manually check millions of auctions a day), so they wait for a report, wait for an item to pop up in searches for certain keywords, and do a quick scour of their recent auctions occasionally. There's also ways around it. Quite often, you can message the auctioner and deal with them off eBay. But eBay do monitor contacts and they often block sellers because they have suspicious histories of what they sell and how they sell it.
eBay have a scheme where people can register interest in certain copyrights/trademarks, Microsoft, Sony, etc. are part of that, but they rarely file a complaint themselves - they just have an written undertaking with eBay that eBay will try to prevent sales of certain things. You'll find that's what gets your auction blocked, not an actual complaint from a copyright holder - there are just too many auctions to monitor them all even by keyword-searching. eBay have automated systems that they will add keywords to if you are large enough and sign up to their scheme, though. Even grey-imports and pre-release hardware have been taken off eBay in the past because of it.
