Following the unsettled copyright fiasco surrounding Google's YouTube, Viacom Inc. said this morning that it is suing Google Inc. for $1 billion for the unauthorized use of its programming online.

Google has been under increasing pressure to find a method of monetizing YouTube, and this lawsuit poses a major challenge to that ambition. Viacom is accusing Google and YouTube of "massive intentional copyright infringement."

"YouTube's strategy has been to avoid taking proactive steps to curtail the infringement on its site," Viacom said in a statement. "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."

Viacom pulled its programming from YouTube last month. It contends that the clips have been viewed more than 1.5 billion times.