We (along with several other news outlets) missed this when it first happened, but apparently Valve did something back in September that it has never done before. After shutting down the multiplayer servers for Square Enix's Order of War: Challenge due to low traffic, Valve then went and yanked the game from user libraries on Steam of those who had purchased a copy. To the best of our knowledge, it's the first and only time Valve has done such a thing.
That's not to say Valve has never removed a game from Steam's store front, but in cases in which it has, purchased copies have always remained in user libraries. In this case, however, by shutting down multiplayer servers, users were left with no way to play the game.
Forbes, which picked up on the story courtesy of a Reddit post, notes that the game has 18 single-player campaigns to play through, but since Square Enix implemented an always-on DRM scheme and than abandoned the title, even that portion of the game remained unplayable.
Order of War: Challenge was never hugely popular to begin with, but still managed to spark a debate over whether or not Steam should have removed the title altogether. If nothing else, it's a reminder that you don't actually own games purchased through Steam -- you're granted a license to use them, and nothing more.
"The game was multiplayer only and the developer is now no longer hosting servers. However user's are complaining that it was removed because they were still able to play the game using tunneling software, such as Hamachi etc., in order to create online LAN-like environments. Now this is no longer possible, since they instead just removed the game entirely," Reddit user 'tsstssk' points out.
As 2013 comes to a close, let that be a reminder that we still live in a DRM-ruled world where it's anything but cut and dry.