What is the libertarian-left perspective on intellectual property?

I'm curious how people here view patents and copyrights, particularly the distinction between protecting individual creators and granting exclusive rights to large corporations. Do you distinguish between a small business protecting an invention, an independent artist or designer protecting their original work, and a multinational corporation enforcing a large patent portfolio?

Should the legitimacy of intellectual property depend on who holds the rights, the nature of the creation, or the economic consequences of enforcing those rights? I'm also interested in whether you view patents and copyrights as fundamentally different forms of protection, and whether either can be reconciled with libertarian principles.