D'oh! Twentieth Century Fox has subpoenaed YouTube to reveal the identity of users who uploaded four episodes of the TV series "24" and twelve episodes of "The Simpsons," Google Watch has learned.

The subpoena reads, in part:

On or about January 8, 2007, Fox became aware that a subscriber ("the Subscriber") of YouTube Inc.s' Internet-based service uploaded pirated copies of the works onto YouTube, making it available for illegal viewing over the Internet to anyone who wishes to watch it. Fox has not authorized this distribution or display of the works. The subpoena request YouTube, Inc. to disclose information sufficient to identify the Subscriber so that Fox can stop this infringing activity.

YouTube declined to comment. A phone call to Fox's legal representation was not returned.

The subpoena includes the testimony of Jane Sunderland, vice president of content protection and anti-piracy for the Fox Entertainment Group.

Sunderland's portion of the subpoena, which is her personal testimony that the infringing activity is occurring, says that Fox has been unable to determine on their own who has been uploading the Works. The uploaded Works are also causing Fox irreparable harm (standard legal language).

Sunderland also testifies that Fox sent an official letter to YouTube on January 8. Although I haven't been in touch with News Corp yet, I assume YouTube didn't remove the videos promptly enough, hence the official subpoena.

A quick search on YouTube only revealed trailers for "24," although given how poorly the site's search function works some videos may yet exist. There are several Simpsons excerpts available, though I didn't see any full episodes. 

Update: Andrew Wallenstein and Carl DiOrio at The Hollywood Reporter have more details about the subpoena, including the YouTube user's name (ECOTotal) and that a subpoena was also served to a site called LiveDigital.