You Paid For It. But Is It Yours?
By far the most controversial feature of Steam, and other game distribution networks like it, is that your games are tied to an account. This is, in part, what makes Steam so useful. Because your games are tied to an account, you only need that account to gain access to your games. Should you reformat your hard-drive, you simply need to login into Steam and leave it running in the background while it downloads and re-installs your games.
However, the need for an account also raises a nasty question: do you really own the games that you buy on Steam? When you purchase a Steam game, all you are doing is downloading a copy of the game. You do not own the disk. You have no ability to resell the game at a later time if you decide you're tired of it, and you do not have the ability to lend the game to a friend at will (although some Steam games come with "guest passes" which allow limited access by a friend). The games are also tied directly to Steam, so it is impossible to play the games without Steam running. And since Steam is an online platform, this also means it is impossible to play games you've purchased if your Internet connection goes down.
Its easy to see the problem. When you buy on Steam, you're not really buying the game so much as the right to play the game. Some people may be fine with this, but I am wary. I believe consumers should retain the right to do what they please with products they've purchased, and so I view Steam's approach as problematic. Steam may say it is DRM free, but that is simply a bending of the truth. Steam games don't carry specific DRM software, but Steam itself acts as a way of managing how the player uses their games.
This is important to remember before taking the plunge and buying games on Steam. Steam offers numerous games, and should you choose to start purchasing games using the Steam service, you are going to become linked to the service. There is no going back. You can't return your Steam games, you can't re-sell them. If you were to lose Internet access for some reason, or you were to tire of Steam, then tough luck. You're stuck. At first, this doesn't seem like a big deal. But if you buy, say, four big titles from Steam, then you've probably just laid down $150-$200 dollars, all of which is at risk if your ability to connect to Steam or access your Steam account is ever interrupted.