MTV owner Viacom Inc. said Tuesday it has sued YouTube and its corporate parent Google Inc. in federal court for alleged copyright infringement and is seeking more than $1 billion in damages. Viacom claims that the more than 160,000 unauthorized video clips from its cable networks, which also include Comedy Central, VH1 and Nickelodeon, have been available on the popular video-sharing Web site. The lawsuit marks a sharp escalation of long-simmering tensions between Viacom and YouTube. Last month Viacom demanded that YouTube remove more than 100,000 unauthorized clips after several months of talks between the companies broke down. In a statement, Viacom lashed out at YouTube's business practices, saying it 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." Viacom said YouTube's 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."