Monday, a panel of the U.S. Court of Appeals for the 9th Circuit held for Lenz, saying that when Universal issued its takedown notice — asserting with certainty that Lenz was violating Prince’s copyright — it did not not consider whether her video was a fair use. If indeed it was a fair use, the company could not have had it removed.

“Universal faces liability if it knowingly misrepresented in the takedown notification that it had formed a good faith belief the video was not authorized by the law, i.e., did not constitute fair use,” wrote Judge Richard C. Tallman for the majority. “Here, Lenz presented evidence that Universal did not form any subjective belief about the video’s fair use — one way or another — because it failed to consider fair use at all, and knew that it failed to do so.”

“To be clear,” the panel said, “if a copyright holder ignores or neglects our unequivocal holding that it must consider fair use before sending a takedown notification, it is liable for damages.”

...

What does the ruling mean for the average YouTuber? It’s hard to tell. But reading its definition of “fair use,” taken directly from the law and the opinion, could provide some protective tips:

It may be fair use when “for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include —

(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;

(2) the nature of the copyrighted work;

(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and

(4) the effect of the use upon the potential market for or value of the copyrighted work.

The definition of "Fair Use" is still quite unclear to me.