via MarketWatch:

On May 24, lawyers for Viacom Inc.’s Paramount Pictures convinced a federal judge in San Francisco to issue a subpoena requiring YouTube to turn over details about a user who uploaded dialog from the movie studio’s “Twin Towers,” according to a copy of the document.

YouTube promptly handed over the data to Paramount, which on June 16 sued the creator of the 12-minute clip, New York City-based filmmaker Chris Moukarbel, for copyright infringement, in federal court in Washington.

That YouTube chose to turn over the data, rather than simply remove the offending video from its site — as it did Friday when it agreed to take down 30,000 videos at the request of a group of Japanese media companies — came as a surprise to copyright experts.