If you have an interest in copyright, open access, and culture, you might want to check out YouTomb, a research project of MIT Free Culture, a student organization at the Massachusetts Institute of Technology. YouTomb tracks videos on YouTube that have been removed for alleged copyright violations. Copyright holders can submit takedown notifications under the Digital Millennial Copyright Act that cause YouTube to remove the video. YouTomb continually monitors the most popular videos on YouTube for copyright-related takedowns, and provides information about the video, including how many days ago it was removed, how long it had been viewable, and the name of the copyright holder. There's more about YouTomb here.
Ernster, the Virtual Library Cat