Keep Your Copyright To Yourself
This example of what Henry Jenkins has characterized as the "vaudeville" aspect of YouTube has a distinctive copyright disclaimer at the end, which reads "All material copyright its respective copyright holder." Given the value of imitation and replication to all aspects of our society, as Hillel Schwartz's The Culture of the Copy notes, this expression of anxiety about possible litigation in what would have to be considered a relatively feeble gesture of legalese is particularly ironic if these rapid fire homages depend on sourcing the original.
Certainly YouTube is also frequently used to "out" those who appropriate the original material of others without attribution, as The Boston Globe has pointed out in coverage of the Rogan-Mencia rivalry between stand-up comics and the LA Times makes clear in reporting on a copyright spat involving Avril Lavigne's pop hit "Girlfriend."
Besides, as Virtualpolitik pal James Kotecki has pointed out, all of the presidential candidates seem to be violating YouTube's copyright policies much more flagrantly.