In their opening briefs in the Viacom vs. YouTube lawsuit (which have been made public today), Viacom and plaintiffs claim that YouTube doesn't do enough to keep their copyrighted material off the site.
Turns out that for years, Viacom continuously and secretly uploaded its content to YouTube, even while publicly complaining about its presence there. It hired no fewer than 18 different marketing agencies to upload its content to the site. It deliberately "roughed up" the videos to make them look stolen or leaked. It opened YouTube accounts using phony email addresses. It even sent employees to Kinko's to upload clips from computers that couldn't be traced to Viacom. And in an effort to promote its own shows, as a matter of company policy Viacom routinely left up clips from shows that had been uploaded to YouTube by ordinary users. Executives as high up as the president of Comedy Central and the head of MTV Networks felt "very strongly" that clips from shows like The Daily Show and The Colbert Report should remain on YouTube.
Viacom's efforts to disguise its promotional use of YouTube worked so well that even its own employees could not keep track of everything it was posting or leaving up on the site. As a result, on countless occasions Viacom demanded the removal of clips that it had uploaded to YouTube, only to return later to sheepishly ask for their reinstatement. In fact, some of the very clips that Viacom is suing Youtube over were actually uploaded by Viacom itself.
You can read some amazing internal emails showing the deceit and how corporate media works-http://www.google.com/press/youtube_viacom_documents.html