Precisely my point. The buyer now has the legal version of the game. Should the copyright cops come knocking for whatever reason, the buyer can wave said bit of paper with a transaction number and prove that he or she is the legal owner.

What the seller has done is tantamount to downloading a copy off The Pirate Bay or whatever the popular piracy platform may be these days.

Do you try to be funny? Because it's not but rather really low level of conversation. This shouldn't happen here. I find this approach disgusting.

Yet the problem remains on what you do when you are the second (or anybody after the first) buyer from a scammer. Than the secret copyright police can demand that you delete the game, because you don't have a legit license. It can't be gained on good faith. So the scammed seller would be a "unintended pirate". The right holder could actually demand satisfaction on the grounds of unjust enrichment, which the buyer then would have to get back from the scammer.

Therefore my reasoning that this is really only attractive for scammers (unless it is DRMed software)

Hence my suggestion above.

But would GOG have to assist in this?

I know my interpretation of that ruling is a lot more restrictive than yours. But isn't it a bit of a stretch to go from "do no obstruct" to "assist in sale".

What I'm afraid is that GOG might just do that because they are way to nice for their good.

In the case of GOG, they don't have to assist in this, because they're not actually hindering the sale in any way. It is possible to copy it onto disc (or send the file), provide the proof of purchase and send all the stuff to the buyer.

The problem, as you've stated, is in ascertaining whether the goods are genuine with DRM-free software. DotEmu is likely facing the same conundrum right now.

And therefore, I do think that it would certainly be in GOG's best interests to provide such a system. If they don't, then what you say is right - it opens the door to scammers who will be profiting massively off GOG's work without paying for it. That, and without any intervention on GOG's part, the game remains available for download on the seller's page.

I don't want that, and I'm sure you don't want it either. It's all about good PR really - encouraging the user to make sure that they are paying for genuine goods.

Of course, Steam, Origin and Uplay are entirely different kettles of fish. They are actively obstructing (opposing) the resale, which would require them to provide such a system.

I don't see any reason why GOG would want to do that. If people are stupid enough to effectively pay for a pirated version just to save a few bucks, than it is their problem more then GOGs.

GOG is doing well with the piracy it is facing. Illegitimate resellers would hardly hurt them any more if it is publicly known that most of them are scammers. But if they start legitimizing this, they might be actually facing a loss of income.

In the end, if people would rather buy three GOGs and pirate three more it would still be better than buying six from a reseller (and potential scammer) that will use the money on drugs and hookers (or Steam!). At least that is my opinion. Which is always right.