Michael Perelman wrote: > intellectual property is an abomination in its present > form. Libertarians used to oppose it as monopoly. What > happened to contemporary Libertarians? My sense is that modern libertarians oppose patents but support copyright. I am thinking of Rothbard (e.g., <URL:http://www.ccsindia.org/lacs/7patents_copyrights.pdf>) but in the software arena I suppose one might also think of the higher profile Richard Stallman. That does not answer the crucial questions: what is covered by copyright, and how long does copyright last? I assume Rothbard would construe copyright narrowly and then make it permanent, but I cannot cite evidence for that. In the US, both copyright and patents have a clear constitutional justification: Congress has the right to create copy rights and patent rights to the extent that this promotes "progress" <URL:http://www.usconstitution.net/const.html#A1Sec8> It may seem obvious to an economist that Congress has exceeded this constitutional mandate in the copyright area, but recall that Lessig lost his argument in front of the SCOTUS by a brutal 7-2. One thing that keeps this all a mess is that in 1790 Congress passed a copyright law which applied retroactively. This has been interpreted to say that the founders did not believe copyright extensions to violate the "limited times" requirement. From a modern economist's perspective, there is retroactive application raises problems for the progress justification as well. Cheers, Alan Isaac