AMERICA: Media giant Viacom today launched a billion dollar lawsuit over popular video-sharing site YouTube and owner, Google.

Viacom is seeking the damages - around £500m - for "widespread copyright infringement".

Viacom claims YouTube has displayed nearly 160,000 unauthorised clips from its cable networks, which also include Comedy Central, VH1 and Nickelodeon.

The lawsuit, filed in the New York District Court, marks a sharp escalation of long-simmering tensions between Viacom and YouTube.

It's the biggest confrontation to date between a major media company and the hugely popular video-sharing site, which Google bought in November for around £800m.

YouTube's soaring popularity has been a cause of fascination, but also fear, among the owners of traditional media outlets.

They worry that YouTube's displaying of user-uploaded clips from their programmes - without compensation - will lure viewers and advertising away from cable and broadcast television.

MTV owner Viacom is especially at risk because many of its shows, which include The Colbert Report and South Park are aimed at younger audiences, who also are heavy internet users.

While YouTube has yet to generate much revenue, its online traffic has been growing rapidly.

According to comScore Media Metrix, YouTube attracted 133.5 million visitors worldwide in January, up from 9.5 million a year earlier.

The lawsuit comes nearly six weeks after Viacom demanded that YouTube remove more than 100,000 unauthorised clips after several months of talks over licensing arrangements between the two parties broke down without agreement.