YouTube uses its users to steal from the work of honest artists toiling to create original content, says Viacom as it finally sues YouTube for “massive intentional copyright infringement”:

YouTube is a significant, for-profit organization that has built a lucrative business out of exploiting the devotion of fans to others’ creative works in order to enrich itself and its corporate parent Google. 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. In fact, YouTube’s strategy has been to avoid taking proactive steps to curtail the infringement on its site, thus generating significant traffic and revenues for itself while shifting the entire burden – and high cost – of monitoring YouTube onto the victims of its infringement.
Viacom Press Release

Viacom wants $1 billion in damages and an injunction stopping YouTube from showing any more of its content.