Hammer of Truth: Stephen Gordon uses an analogy of a rumour to deal with copyright issues. He argues that if someone overhears a rumour being told between two people that person is not under any obligation to honour any "don't tell anyone else" clauses. He then says that people downloading copyright infringing music should be left alone as a third party -- the contract was between the content owner and the purchaser.
I don't think that follows -- considering Gordon is refering to the practice of downloading music from p2p systems the third party is more like someone who actively seeks the rumour, for example by eavesdropping. True, the person relaying the rumour (putting the content on the p2p network) is eagerly breaking the agreement not to pass it on, but the third party has to actively go to their metaphorical house specifically to get the rumour. They're not really that innocent.