Viacom International and a host of content providers asked a federal appeals court yesterday to reverse a decision dooming their claim that YouTube is liable for $1 billion in damages for copyright infringement.

Attacking a 2010 grant of summary judgment to YouTube under the safe harbor provision of the Digital Millennium Copyright Act, lawyers for Viacom, The Football Association Premier League Ltd. and other plaintiffs argued that YouTube clearly knew it was committing copyright infringement on a massive scale, and the providers asked the U.S. Court of Appeals for the Second Circuit to send the case back to the district court for another round.