Updated below to include statement from Google: Exasperated by the failure to reach an agreement with Google and YouTube after months of negotiations, Viacom sent Google a letter today demanding that all Viacom material on YouTube—100,000 plus clips representing 1.2 billion streams, according to Viacom—be removed immediately. The clips span MTV Networks, BET and Paramount. Viacom wants a deal similar to those already reached by music labels and CBS. I’m not completely sure what the sticking points are on either side; Viacom and YouTube have managed a small marketing deal in the past but the media company also has made take down demands before. This, however, is the most sweeping.
In a statement, Viacom also cites the lack of filtering software long-promised by YouTube:
“Filtering tools promised repeatedly by YouTube and Google have not been put in place, and they continue to host and stream vast amounts of unauthorized video. YouTube and Google retain all of the revenue generated from this practice, without extending fair compensation to the people who have expended all of the effort and cost to create it. The recent addition of YouTube-served content to Google Video Search simply compounds this issue. .... Our hope is that YouTube and Google will support a fair and authorized distribution model that allows consumers to continue to enjoy our very popular content now and in the future.”
Update: Viacom and Google have a complicated relationship. The two partnered in a high-profile AdSense test involving MTVN clips and promos. Google Video’s first version included unauthorized Viacom content. As for Viacom and YouTube, much was made of their marketing deal last March—YouTube needed to show it could work with major content owners—but it was just a one off. When I asked a source about the sticking point here, the answer was “it’s probably money as usual ...” Google’s decision to include YouTube in its video search escalated the situation for Viacom, since it increases the chance for money to be made off of advertising against the clips. Another concern internally: the kind of advertising sold against clips from its tween and kids programming. Viacom wants control over the ad environment for those shows.
Update II: Viacom delivered a detailed list to YouTube this morning—the DMCA requires specifics—and the site promises to comply: “It’s unfortunate that Viacom will no longer be able to benefit from YouTube’s passionate audience which has helped to promote many of Viacom’s shows.  ...  We take copyright issues very seriously. We prohibit users from uploading infringing material, and we cooperate with all copyright holders to identify and promptly remove infringing content as soon as we are officially notified.  We will continue to work with content partners large and small to provide them with a platform to promote their content and engage and grow their audiences.”
Related:
-- Viacom, Google To Test MTVN Clips with AdSense; MTVN Downloads For Sale