If a game had exclusive pre-order DLC (or a goodie that was removed), isn't it technically possible to acquire these items from someone whose account contains them because GOG is DRM free? I was wondering this because a new competitor to Steam touts the ability to resell digital games, which if extended to all digital content concerning the game would be a tremendous improvement for people such as myself who would like to own complete games, but GOG is DRM-free, so that creates problems, leading to the alternative described above. What do you think?

GOG does try to get all DLCs for games. Pillars of Eternity's preorder dlc was included for example in the definitive edition from what I heard. For me the new service wouldn't matter as I'm a collector, I wouldn't trade in any of my games.

The new service wouldn't so much be the collector trading his games, so much as the collector trading some game for a more complete version of one that isn't available. This would also do wonders for legally obtaining de-listed games.

I do not endorse piracy; when I made this post I was referring to add-on content that was unobtainable, with the notion that one already owns the game on their account. Perhaps that could have been made clearer. If I have already bought the game, and/or the game/content can literally not be bought anywhere, then I do not feel this scenario should be stigmatized alongside piracy. Pirates don't want to pay money; I do, but can't because of impediments concerning the companies. This paragraph is not meant to demean you, just to clarify my statements.

This paragraph, however, IS meant to demean you, you knob.
;P

There are also those who want to experience a piece of media that is no longer being sold for whatever reason, so they go to piracy (see No One Lives Forever, for example).

The fact that the content is not being sold does not mean that it's freeware or otherwise freely available. As long as copyrights are being held, and the copyright holders have not explicitly made it freely available, making an unauthorised copy is piracy (and if there is no copyright, or the owner of it have said that the product is free for all, all copies are by definition authorised).

There are a rare few cases where GOG have removed content from purchased games (I don't remember any of them, so I cannot name them), but in most (if not all) of them, that is because GOG realised they didn't have the right to sell the content to begin with, and as such, the customer don't have the right to have it either (you can't rightfully purchase something from someone who's not allowed to sell).

In the one case I do know about, the game was removed from the store, and later added back without some content as an entirely different product, and as such, earlier customers were not affected. This case is due to a change of publishers, and the new publisher did not agree for GOG to sell that content. That's very mean of you, you egg.

If GOG no longer has the authority to sell a game, why do you think they would have the authority to transfer a license for it?

It's a lose-lose then. No one profits off the work, and no one enjoys it. If the parent company never releases it, you'd have to pray that it survives until it reaches the public domain in 95 years (no really) and that's if companies like Disney don't extend that time any more. When faced with such a dilemma, I doubt there's a 100% good option; you have to sacrifice something.

Because the gifts were bought while GOG still had the permission to sell the games. Why should they? Just because GOG can no longer sell new copies? With that train of thought, then GOG should also remove said games from accounts. I doubt it's even close to possible. You're talking about a service that would require the cooperation of a publisher that is no longer able/willing to work with them.

1. Don't some gift codes expire? I believe I've heard about that in the threads.
2. I also hear that GOG has removed goodies from games. Though not the games themselves, it does show GOG can take away something you paid for. When you bought the game, you bought the whole package; the goodies weren't free, you had to buy them. Other companies remove games (usually free, I admit), and make it legally impossible to re-download them, like PT. If GOG, for whatever reason, took away my right to a game I purchased, it would be no different to when Nintendo or Sony did the exact same thing.
3. I was describing the services for a new upcoming digital retailer called "Robot Cache" that aims to compete with Steam and GOG. I am hoping that this company does well enough to have other companies imitate its feature of selling digital games one owns, including GOG and Steam. As previously stated, we'll have to see how and if that system works.

It does seem like this debate is getting heated. It is not my intention to offend anyone's beliefs about international copyright law.

I hope so too.

One can hope.

No. Bonus codes do expire though.
A gift code is a code bought as a gift through the checkout screen. A bonus code is a code provided for free (possibly along with other stuff). If you paid GOG for the code, the code shouldn't be expiring.
Another difference between bonus codes and gift codes is that gift codes can be partially redeemed, while bonus codes can only be redeemed once, and any games not redeemed from them are lost.
It used to be easier to distinguish between bonus and gift codes due to their format, but that no longer seems to be the case.