Cory Doctorow has a very interesting article, How Copyright Broke, in the September Locus magazine.
I really like this analogy he made:
Indeed, until the photocopier came along, it was practically impossible for a member of the audience to infringe copyright in a way that would rise to legal notice. Copyright was like a tank-mine, designed only to go off when a publisher or record company or radio station rolled over it. We civilians couldn't infringe copyright (many thanks to Jamie Boyle for this useful analogy).