YouTube sued

It has finally happened. Reuters reports that Viacom has sued YouTube in the US for $1billion for copyright infringement. Said Viacom:
"YouTube's strategy has been to avoid taking proactive steps to curtail the infringement on its site…Their business model, which is based on building traffic and selling advertising off of unlicensed content, is clearly illegal and is in obvious conflict with copyright laws".
The IPKat says that there’s clearly primary infringement going on by the uploaders. The question is, can YouTube be made secondarily liable? If what Viacom says is correct, and the business model does rely on facilitating infringement then things look pretty grim for YouTube (unless they come up before a court that wants to limit the affect of the Supreme Court’s Grokster decision). However, it’s hard to comment on the business model without having access to information which, at this stage, presumably remains confidential to YouTube. One way out of Grokster’s pull of gravity might be for any court to note that YouTube has changed hands since it was set up, and so the original business model may not remain relevant.