Update: It's back up. McIntosh's YouTube comments says, "Three weeks after a bogus DMCA takedown by Lionsgate, I received a one line email from the YouTube team saying that my remix has been reinstated."
Jonathan McIntosh's "Buffy vs Edward" video is a classic: a mashup that's been viewed millions of times on YouTube, discussed in the halls of the US Copyright Office, and cited in a Library of Congress/Copyright Office report as an example of legal, fair use mashup.
But when Lionsgate bought out Summit Entertainment, the company that made the Twilight franchise, they started to aggressively "monetize" the remixes of the series online. That meant that they claimed ownership of them using YouTube's ContentID system, which would automatically place ads alongside all the video clips from the series -- including "Buffy vs Edward."
McIntosh objected to this. His video was fair use -- the Copyright Office itself said so -- and had never had ads placed in it. Lionsgate had no claim over it. He appealed to YouTube. YouTube punted to Lionsgate, who insisted that they were legally in the right. McIntosh hired a lawyer to write an letter explaining the fair use analysis to YouTube, who agreed, and reinstated the video, and Lionsgate (seemingly) dropped the claim.
But Lionsgate came back with another claim: the "audiovisual" elements in the video were fair use, but the "visual" elements were not (yeah, I know). McIntosh went through the process again, with the same result -- and so Lionsgate filed a complaint with YouTube that resulted in it being taken offline altogether.
McIntosh's correspondence with Lionsgate has been very unsatisfying. The company claims that since he refused to let them make money off of his creativity, they had "no choice" but to have it censored from YouTube. The company's representatives refuse to address the fair use claims at all.
Meanwhile, to add insult to injury, McIntosh had to complete an insulting "copyright education" course in order to continue using YouTube (even though he is an expert on fair use and had done no wrong), and is permanently barred from uploading videos longer than 15 minutes to the service -- all because of the repeated, fraudulent assertions made by Lionsgate.
In the past, companies that sent similar fraudulent takedowns to YouTube have faced penalties (remember EFF and the dancing baby versus Prince and Universal Music?). It would be an expensive and difficult proposition for McIntosh to bring Lionsgate to court for repeating the fraud, but let's hope that these copyfraudsters don't get off scot-free.
In the meantime, here's a really cool version of the video with annotations courtesy of Mozilla's popcorn.js tool.