20th Century Fox served YouTube with a subpoena Wednesday, demanding that the Google-owned viral-video site disclose the identity of a user who uploaded copies of entire recent episodes of "24" and "The Simpsons."

The subpoena, which first came to light on the blog Google Watch, was granted by a judge in U.S. District Court in San Francisco after being filed Jan. 18 by the News Corp.-owned studio. It is not yet known whether YouTube has complied with the request.

In addition, lesser-known video site LiveDigital was served with a similar subpoena. A spokesman for LiveDigital confirmed the company received the subpoena and intended to comply immediately.

A Fox spokesman confirmed the subpoenas were filed and served but declined further comment. A spokesman for YouTube declined comment.

The "24" episodes in question actually appeared on YouTube before their primetime Jan. 14 premiere on the Fox broadcast network, which spread four hourlong episodes of the hit drama over two consecutive nights. Fox became aware thst the episodes were on YouTube on Jan. 8, according to the subpoena.