contracts can prevent you from doing things that copyright would normally allow you to do
Edison Eula closeup CC BY-NC-ND Fouro Boros
If only Thomas Edison had figured out that "taking action to agree" thing, we could've had EULA's nearly a century earlier!
Most US courts will happily enforce almost -any- contractual terms that are not illegal, or so incredibly unfair or morally reprehensible as to be "void as against public policy". You can (and almost certainly do, on a daily basis) contract away your right to take someone to court - often by agreeing to "binding arbitration" instead. Courts frequently enforce arbitration clauses.
Examples of limitations on your use - copyright-wise - that I'm fairly certain many of you have already agreed to (I've agreed to one of them, but not the other):
- Got iTunes? You've agreed that "(i) You shall be authorized to use iTunes Products only for personal, noncommercial use." Copyright law allows you to use things for commercial purposes without permission if your use is a fair use, but it's a violation of your iTunes contract to use those materials for a commercial fair use.
- Got Netflix? You've agreed that "THE NUMBER OF DEVICES ON WHICH YOU MAY SIMULTANEOUSLY WATCH IS LIMITED." Watching movies in your own home does not actually implicate copyright law (unless you are doing some very weird movie-watching). So as far as copyright goes, you can watch as many things as you want on as many devices as you want, forever and ever and always. But Netflix gets to set a limit for you, and trying to exceed that can violate your contract.
A couple of people have asked me "can you point to case law where a court said a contract could limit use of public domain materials?" This was mostly in discussions about limitations archives and museums (or electronic database vendors) impose on use of older materials in which the copyright has expired - and I am not familiar with a case specifically on those facts.
However, I'm familiar with the ProCD case, in which the Seventh Circuit upheld a clickthrough license that limited use of a phone database. They specifically confirmed that the phone database was not covered by copyright, but that commercial use was prevented by the contract. Most discussions of the case focus on the court's interpretation of whether the clickthrough license was enforceable, but the copyright ruling is also pretty clear. (Though the ProCD opinion did say that the contract terms weren't preempted by copyright because they didn't overlap with copyright rights, and I don't know if that's been cleared up since, and is it clear yet that I don't have Lexis or Westlaw access?)
"So what?" you say, "Apple's not going to sue me for breach of contract!"
Nope, but they could choose to terminate your account.
More on that, and on contracts that you did not personally agree to - sometime in the next few days.