Via BoingBoing comes all of Title 17 of the United States Code, which encapsulates all of American copyright law, in short quartains with ABAB rhyming scheme. On 17 USC 107 (fair use):

Despite all of these rights
All people can reproduce
To report, criticise, or teach
Because that is fair use

Almost as interesting as the verse is the copyright notice included at the bottom of the post:
Copyright 2006, Yehuda Berlinger. Permission is hereby granted to copy in part or in whole along with this notice, attribution, and a link back to this web site.

Technically I have filled Yehuda's requirements by including his copyright notice, but it would not matter if I did not - I am reporting on his writing, and so am covered under fair use.