The case will be a major test of the Digital Millennium Copyright Act of 1998, which protects online companies that carry copyrighted material posted by others. Viacom says YouTube doesn’t qualify, because it actively participates in posting videos and it profits when users share them.

THE PLAYERS

Viacom
The $30 billion mega-parent of Paramount Pictures, Nickelodeon, Comedy Central, and more. Sumner Redstone, 84, is its majority owner.

YouTube
The world’s biggest online video site, which was acquired by Google last year for nearly $1.7 billion.

THE POSITIONS

Viacom
Argues that each time a Viacom clip appears on YouTube, it’s a copyright violation. (So far this year, the company has asked YouTube to take down 220,000 clips.) Viacom wants a licensing deal with YouTube and payment for clips that have appeared on the site.

YouTube
Responds that it’s an online forum and can’t be responsible for policing content; says it removes ­copyrighted videos as soon as it’s made aware of them. (YouTube already has licensing deals with CBS and NBC Universal.)

THE EVIDENCE

Viacom
In February, Viacom asked ­YouTube to remove a video of pop star Shakira’s Grammy-nominated song “Hips Don’t Lie.” According to Vidmeter.com, the clip had been viewed 6.8 million times.

YouTube
In a single weekend in February, YouTube staffers removed 100,000 clips at Viacom's request. YouTube also says it's testing new technology to identify copyrighted clips that have been illegally uploaded to its site.  

THE LANGUAGE

Viacom
“YouTube’s brazen disregard of the intellectual property laws fundamentally threatens…one of the most ­important sectors of the United States economy.”

YouTube
“Viacom’s complaint threatens the way hundreds of millions of people legitimately exchange information.” 

THE LAWYERS

Viacom
Don Verrilli, 50, partner at Jenner & Block in Washington. Verrilli represented MGM Studios and ­others before the U.S. Supreme Court in 2005, helping to shut down the music-swapping site Grokster.

YouTube
David Kramer, 39, partner at Wilson Sonsini Goodrich & Rosati in Palo Alto, California. As a law student, Kramer took a First Amendment class from Verrilli. Grade: A.

THE MONEY

Viacom
Asking for $1 billion in damages.

YouTube
“The lawsuit is without merit at any dollar figure.”

PRESIDING

U.S. District Judge Louis L. Stanton. The 79-year-old Reagan appointee ordered Yasir Arafat to be deposed in 1996 in a case brought by the family of Leon Klinghoffer, the wheelchair-bound man killed aboard the hijacked cruise ship Achille Lauro.