Amazon.com has patented has patented the "one-click" ordering innovation, this is an example of a business methods patent copyright trade secret public domain use of intellectual property Some companies are in the business of buying up patents and looking for the infringers of these patents, these companies are referred to as: patent trolls trade secret businesses patent specialist patent resellers Non-copyright holders may use copyrighted material for a limited and specific purpose under: fair use creative expression Digital Rights Management possessions rules Creative expression is protected through which body of intellectual property law? copyright patent trade dress trademark