Someone raised a question about the monkeys and copyrighted works. Allow me respond to that briefly. If an infinite number of monkeys create an infinite amount of work, and some of that work just happens to be an MP3 of Metallica's latest hit, the work is free from American copyright restictions. This falls under one of the four main "limitations" of copyright:

Idea
Ideas expreesed by creative works are not themselves protected. Copyright covers the work, the expression of ideas, but not the ideas themselves. That is what patents are for.

Facts
Plain facts, like, say, a phone book, are not protected. However, cataloguing or organizing facts in a certain way can sometimes result in the database or collection of facts being copyrighted.

Independent Creation
If an exact duplicate of a work is created independently and with no knowledge of the original, it is not a copyright infringement. Providing you can prove it.

Fair Use
The one most well known. The Fair Use doctrine says that creative works can sometimes be used, in whole or in part, in specific circumstances, without violating copyright. Fair use is constantly being redefined.

As you can see, the third limitation is what makes this okay. Additionally, if the monkeys are in a nation that does not have an agreement with America, where Metallica received its copyright, then this statuatory analysis is not even required.