Comment by tzs

> If I buy a book or CD [...]

Note: I'll use US law here.

There's an important legal difference between books and CDs, which I'll get into at the end of this. For now let us just look talk about books.

> I can keep that copy forever, sell it, lend it, donate it, give it away, or let my kids inherit it

The works because the way most of us acquire copies of books doesn't involve entering into any kind of contractual arrangement with the copyright holder, so as long as what we want to do does not violate the copyright owner's copyright rights we can do anything with that book that we'd be legally allowed to do with a similar physical object (say a blank notebook).

Copyright law does give the copyright owner the exclusive right to distribute copies but there is an exception, the first sale doctrine, that says the owner of a particular lawfully made copy does not need permission from the copyright owner to "sell or otherwise dispose of the possession of that copy".

If we bought our books through some channel where they could require us to agree to a contract in order to be allowed to buy they could include restrictions on what you can do with the copy, just like game companies do.

It would be hard to enforce since they would have to do it by suing people who violate the contract which would be impractical almost all the time.

Compare to digital goods, especially executable digital goods, where they can make it so using your copy requires checking in with a server of theirs which can refuse to let you use the thing if it thinks whoever bought it has broken the contract.

The important legal difference between books and CDs is that exception to the first sale doctrine, the one that says you can "sell or otherwise dispose of the possession of that copy" without copyright owner permissions does not fully apply to CDs, has an exception to the exception.

The exception to the exception says that for copies of computer programs and musical sound recordings the outer exception does not apply to disposing of possession by "rental, lease, or lending, or by any other act or practice in the nature of rental, lease, or lending" when it is "for the purposes of direct or indirect commercial advantage". So for CDs if you want to lend them make sure it is not for commercial advantage.

BTW, the exception to the exception also has an exception, making it not apply to embedded systems and console games. (There are also exceptions for libraries).