I’m know for being a little paranoid about violating copyright, but there is the Defend Fair Use side as exemplified by Lawrence Lessig and the Center for Social Media. But somehow, no one justifies the usefulness of allowing users to post parodies & remashes on YouTube quite like Adolf Hitler or Walt Disney. See the clips below:
P.S.: I really have to credit Robin2Go for pointing out the first video.
Defending Hitler Parodies
A Fair(y) Use Tale, Not Quite the Disney Version