True. You are not forcing anyone. However, when you release
something into the public, copyright sort of makes everyone agree
to the contract with you even if they don't want it.
How you can hear something or see something even if you did not
aim to do that, I listed in my response to Michael above.
Kinsella has a whole chapter about copyright as a contract.
To make clear, I am NOT against contracts. If you give me a book
under a contract, it is morally correct to abide by the contract.
Question is, can this duplicate a sort of copyright regime? Kinsella
argues that no. I argue the same. It is practically almost impossible.
One person violates the contract and the closed club of
contract agreements is compromised.