A good resource: http://www.stephankinsella.com/category/intellectual-propert...

And innovations that thrive without IP: http://www.stephankinsella.com/2010/08/innovations-that-thri...

Also: http://mises.org/media/categories/226/Against-Intellectual-P...

and

http://mises.org/journals/jls/15_2/15_2_1.pdf [pdf]