If someone sells me a DVD or a CD on a specific condition – for example that I am not allowed to distribute it to others – then this restriction is a result of freedom of contract. If I don't agree to those terms, I shouldn't buy them, I don't have a right to pretend that I agree and then break the conditions afterwards.But he also says, although does not elaborate, that "[i]t might be that something should be illegal, but that new technologies make it impossible to stop it with legitimate means." Often the only way to enforce the contract above entails invading the privacy, not only of the buyer - who indeed has the right to give up his privacy in order to enjoy the DVD -, but of others. If so, a society that respected privacy would not enforce such contract. If only the privacy of the buyer were at stake, the contract would be enforceable but could lead to the social ostracism of the buyer. For example, I would be remiss to visit a friend who allowed the installation of cameras inside her home.
Notice also that intellectual property rights as currently understood go far beyond contracts between consenting adults. Under the laws of some countries I cannot copy and distribute copyrighted music no matter whether I have signed a contract or not. I cannot, for example, record with a microphone a song that arrives at my window, and then copy or replay the resulting file. Or, to use a more realistic example, I cannot make use of a music file someone has uploaded to a p2p network. Enforcing those laws almost automatically entails invading people's privacy of their homes and their communications without their consent.
I think that intellectual property rights generally conflict with privacy or with physical (non-intellectual) property rights.