Viacom has sued Google, alleging copyright infringement from video-sharing site YouTube and seeking $1 billion in damages.

The lawsuit, filed in US District Court for the Southern District of New York, follows a Digital Millennium Copyright Act (DMCA) request Viacom sent Google last month, which related to the unauthorised posting of Viacom videos to YouTube.

At the time, Viacom demanded that Google remove over 100,000 of its clips from YouTube, which Google acquired last year for $1.65 billion. Google said it would comply with the request.

In escalating its battle with YouTube with this lawsuit, Viacom reiterates that YouTube has allowed and benefited from "massive intentional" copyright violations of Viacom videos.

In addition to $1 billion damages, Viacom is asking the court for an injunction barring Google and YouTube from continuing the alleged infringement, Viacom said on Tuesday in a statement.

Google stands ready to fight the allegations. "YouTube has respected the legal rights of copyright holders," a Google spokesman said via email. "We will certainly not let this suit become a distraction to the continuing growth and strong performance of YouTube and its ability to attract more users, more traffic and build a stronger community," he wrote.

Almost 160,000 Viacom video clips have been uploaded to YouTube without permission and have been viewed over 1.5 billion times, Viacom alleges.

"YouTube is a significant, for-profit organisation 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," Viacom charged in the statement.

Google and YouTube illegally profit from the traffic that the unauthorised videos draw to their sites by selling advertising, according to Viacom, which added that YouTube has been lax in its attempts to stop users uploading copyrighted videos without permission.

Viacom decided to sue Google after negotiations and other measures failed to halt the alleged copyright infringement in YouTube, Viacom claims.

Viacom is a media conglomerate whose properties include MTV, VH1, Nickelodeon, Nick at Nite, Comedy Central and Paramount Pictures.

The case is unlikely to result in a total shutdown of YouTube, because legitimate uses of the site exist beyond the potentially illegal activities Viacom is objecting to, said Sheldon Klein, an attorney specialising in intellectual property matters and a partner at Arent Fox in Washington, DC.

However, Google may find itself liable to the infringement claims if Viacom proves that Google and YouTube didn't do all that was possible to prevent users from uploading copyrighted videos without permission, especially after being served with the DMCA notice last month, Klein said.

Specifically, if YouTube and Google haven't implemented available technology that would allow them to do a better job of filtering out infringing videos, Viacom could have a legitimate argument in saying they're not trying hard enough, he said.

A check of YouTube on Tuesday at 9am GMT showed multiple instances of Viacom-owned videos.

One clip found, for example, has been on YouTube since 5 February this year, while another was uploaded in October last year.

Google executives have said the company is developing technology to address the issue of infringing downloads on YouTube and have promised to deliver it in the near future. Google didn't immediately provide an explanation of what, if any, filtering and detection technology exists in YouTube today.

In the meantime, competitors like News Corp's MySpace, which also lets users upload videos to its site, have licensed third-party systems for detecting infringing videos. There are a number of companies that make this type of software, including Audible Magic, the one chosen by MySpace.