The use of copyrighted material that can be used without permission of the original copyright owner such as criticism, reviewing, news reporting, parodies, remixes, mashups, cover songs, scholarship, and teaching.
Bullshit the feds made to allow your hard work to be stolen without permission, a law that needs to criminalized.
Idiots often use "Fair Use" to excuse stealing your homemade works so they can shit on them, pseudo-intellectual mods will respect this shit even when it's not right.