Copyright protects ``intellectual property', it gives the copyright holder the right to control copying to which the right extends. Net seemed to be the inferno for copyright holders because the laws didn't seem to be enforceable and they required legislative changes. However, with machines like Mark Stefik's demonic ``trusted systems'', the situation may be just the opposite. This time the code enforces copyright, and code may be tougher than law. A trusted system lets the author control every aspect of use. He can control if it can be copied, how many times it is read, to whom it is given, etc. Nevertheless, Intellectual property is not physical property. Unlike physical objects, ideas are not really ``owned''. Once it is given it is no longer yours; its consumption doesn't lessen anything, it multiplies as sun shines. The US constitution acknowledges this difference and protects intellectual property to the extent that sufficient incentive is created. It is given as an exclusive right to promote progress of science and arts, and granted only for a limited time. ``Fair use'' is the limitation of copyright. One can criticize a work using part of it without any permission from the author. Or you can sell it as you wish. There's now an abundance of licenses which are private law that's designed to waive ``fair use'' rights. If trusted systems let the author control use perfectly, then fair use is destroyed.
Lessig suggests that we should choose about two issues. He presents his own choices, but these aren't necessarily the ones you have to make. The point is that there are choices to be made about the architecture of cyberspace. He suggests that we preserve anonymity because we wouldn't like to be grouped according to what we read, and that we should preserve an intellectual commons for it gives our culture great value.