deoren: I mentioned something similar to support and they pointed out that while it's free to download, often there are distribution restrictions in place.
That was something I didn't think of. Perhaps the rights holders would be ok with that though, as it would bring them more attention.
The wikipedia list I linked does mention at least some of the restrictions but what ever the case GOG should always ask permission just to be on the safe side.
lowyhong: I'd be more careful with that link if I were you, as a lot of the games in there aren't exactly "liberated" yet
-edit-
Sorry I just realised that by "liberated", it doesn't mean "freely downloadable games". My bad my bad!!!!! >.<
No problem. Liberated games lists both games released as freeware and games that has had it's source code released (with or without media) so some of the games still need original game to play. It also lists licence they are released under.