It's the headline that many saw coming before the dust even settled on Google's $1.65 billion acquisition of YouTube last year. Legal experts might not have predicted the name of the behemoth that would file a formal complaint against the viral-video site, but a massive copyright infringement suit seemed inevitable to many.

That behemoth, of course, is Viacom. Viacom took its gloves off in a digital-age boxing match that could go many more than 12 rounds as two technology champions duke it out on principle. In a statement it released in conjunction with filing its $1 billion federal copyright lawsuit in the U.S. District Court for the Southern District of New York, Viacom called YouTube 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."

Whether those "fans" to which Viacom referred mind Google making money from the traffic they drive to the video-sharing site is not the issue. Whether the fans are liable in future copyright suits is. According to some legal experts, YouTube's uploading community could find itself in the line of fire.