Thanks to Korotan for The Witcher 2 - Assassins Of Kings key, and thanks to Finkleroy for sending it to me.

Your welcome. I hope you will have fun and that it work.

Thank you.

People keep redeeming games they were not granted. This has gotten way out of hand, so now I need to do something about it. In the rules, I mentioned that it's fine for donors to donate keys that contain multiple games/DLC. It's still okay, but I very strongly recommend making separate purchases in order to receive and donate separate keys instead. The only exception would be if you intend to donate all the contents of a key to the same donor.

THE RULES CLEARLY STATE THAT YOU ARE NOT ALLOWED TO REDEEM ANY GAME OR DLC THAT YOU WERE NOT GRANTED. THIS RULE HAS BEEN REPEATEDLY VIOLATED, AND NOW IT'S TIME TO TAKE ACTION. I'VE BEEN LENIENT UNTIL NOW. I'VE GIVEN PEOPLE THE BENEFIT OF THE DOUBT THAT THEY JUST MADE A MISTAKE BECAUSE THEY WERE NOT PAYING ATTENTION. FROM NOW ON, IF YOU VIOLATE THIS RULE, YOU WILL BE PERMANENTLY BANNED FROM THE GIVEAWAY. NO MORE SECOND CHANCES.

Wow. Didn't expect that to be a common problem. Nor that there'd be any leniency in case it happens, for that matter.
If anyone really does it by accident (which shouldn't happen either, you should be really careful when redeeming a game), should be your duty to immediately notify both finkleroy and the donor, obviously not download any game(s) you were not granted, and submit a support request to have said game(s) changed back into a code to put back in the giveaway, keeping both finkleroy and donor in the loop about the status of the matter. And if GOG support will for some reason refuse to make the exchange, should be your duty to donate (preferably) the game(s) in question back to the giveaway, or at least others of equal or greater value. Until and unless the matter is sorted out, someone who does this shouldn't be allowed to request anything else, should go without saying. And while those who do immediately realize it and apologize and work towards fixing the issue may be allowed to have it kept quiet once, anyone who just takes extra game(s) like this and doesn't immediately notify and get to fixing it must be named and shamed.

Is that why Thief Gold disappeared from the list?

It didn't happen at all until relatively recently, but it's happened a total of four time now. Each time, the person has apologized and explained that they weren't paying attention. It didn't occur to me that it's possible for them to have GOG remove the game from their account and create a new key for it. In the future, if someone does this, I'll lift their ban.
Yes.
Yes. That's happened a few times now, despite the fact that I notify people when I've given them a key that contains multiple games/DLC, and remind them to only request what was granted to them. One of these times, I forgot to notify the recipient that it was a multi-game key, but when you attempt to redeem a key, it should be blatantly obvious that it contains multiple games/DLC, each of which has a check box next to it.

Shouldn't this/these person(s) be shamed in public and/or ostracised in general?

Not if it truly was an oversight. In the future, I'll give them the chance to make things right, and if they don't, I'll permanently ban them from the giveaway. The only way they'd be publicly outed is if they requested a game after they were banned. I'd like to keep drama out of these giveaways as much as possible. There's already enough of that on the internet.

Should they be asked to replace the exact game, or a game of equal value? I am of a mind that it should be the exact game. When people donate a key they do it so that someone will be able to play that precise game.

I agree that it should be the exact game. That's assuming GOG isn't willing to remove it from their account and convert it to a new key.

I don't know if that is something they will do. But I do know that they can remove a gifted game from someone's account and credit the money back to the original purchaser.

There are always black sheep doing their things. GOG forums are no different. Really sad to see certain individuals take advantage of a basic and flawed way of gifting multiple games on GOG. I actually proposed to GOG support a long time ago to give the key owner more tools to control their gift purchases. One of those was the idea to have an option of tagging what games can be reedemed in a multi game gift code, but not luck. Splitting of multi game GOG gift codes is a big no no for GOG, especially when talking about removed games. Cheers

I'm really sad that the giveaway has been abused that way, but I applaud how you're dealing with it. Letting the thing turn into some personal shitstorm would be even worse.