Let's look at a real-world scenario. By default any created work is covered under copyright law (which says no distributions of any kind), but copyright law does allow for custom licenses to be issued.
Let's pull a book off my shelf. The first one happens to be Dune: The Machine Crusade. A page in the beginning state that I may not make copies of it, store it or disseminate it. I may also not distribute it in any form other than the original binding. Therefore I retain the right to resell the book itself (depriving me of it) and to lend it to a friend.
Now, let's look at software. We will take a industry giant (Microsoft) as a case study. The Windows Vista Home Basic EULA is available here:
Some terms from it that drew my attention:
2. INSTALLATION AND USE RIGHTS. Before you use the software under a license, you must
assign that license to one device (physical hardware system). That device is the “licensed device.” A hardware partition or blade is considered to be a separate device.
a. Licensed Device. You may install one copy of the software on the licensed device. You may use the software on up to two processors on that device at one time. Except as provided in the Storage and Network Use (Ultimate edition) sections below, you may not use the software on any other device.
b. Number of Users. Except as provided in the Device Connections (all editions), Remote Access
Technologies (Home Basic and Home Premium editions) and Other Access Technologies
(Ultimate edition) sections below, only one user may use the software at a time
8. SCOPE OF LICENSE. The software is licensed, not sold. This agreement only gives you some rights to use the software. Microsoft reserves all other rights. Unless applicable law gives you
more rights despite this limitation, you may use the software only as expressly permitted in this agreement. In doing so, you must comply with any technical limitations in the software that only allow you to use it in certain ways. For more information, see http://www.microsoft.com/licensing/userights. You may not
14. PROOF OF LICENSE.
a. Genuine Proof of License. If you acquired the software on a disc or other media, a genuine Microsoft proof of license label with a genuine copy of the software identifies licensed software. To be valid, this label must appear on Microsoft packaging. If you receive the label separately, it is invalid. You should keep the packaging that has the label on it to prove that you are licensed to use the software.
Therefore we have two products, both covered under copyright law. One is sold to me and one is not. But interestingly enough, while the book felt it necessary to state that the original binding is required, Microsoft did not. Indeed, the media is never mentioned, other than at the time of purchase. The license is the label, not the media it is on.
Microsoft also has this page http://support.microsoft.com/kb/326246 that states that if I manage to lose/damage my copy of the software, then I will be able to get a copy from them again (at an additional cost). Therefore I can assume that they don't consider the software CD to be anything other than a way to get the software to me, and the lack of possession of a CD does not in any way violate my use of the software.
Why doesn't the game companies fall under the same restrictions, then? Now I have to have BOTH the CD and the license to play. And losing the CD now suddenly voids my license? After all, I lose the ability to exercise my rights in the license.
And it has been suggested we are teenage law-readers. I am in the IT software industry. If a client buys from me, they buy licenses, not software. If they lose the media, I will gladly replace it. If they lose the license key, I will replace it with the one I have on record. There will be an additional fee payable, but it's a token to cover time done to research the original purchase.