NBC and Viacom have filed amicus briefs in support of an independent news service that has charged YouTube with copyright infringement.

While Viacom filed a $1 billion claim against YouTube in March, NBC's decision to join the fray marks the first time the network has taken legal action against the Google-owned company. 

The case at bar pits Robert Tur, an independent news producer, against YouTube. Tur brought the case in California federal court alleging that posts of his 1992 Los Angeles riots footage were illegally displayed on YouTube.

The case is considered an important test because Tur will make the same legal arguments Viacom will have to make in its case against YouTube.

Google has maintained that YouTube is immune from prosecution because of the Digital Millennium Copyright Act (DMCA), which immunizes website publishers from copyright claims if they remove offending content after being given proper notice.

"Under its interpretation of the DMCA, YouTube would be free to set up a business that knowingly infringes copyrighted video works on a massive scale by copying, publicly performing, displaying and disseminating those works," the NBC/Viacom brief read. "Contrary to YouTube's claim that it cannot block content, it is widely reported that YouTube has the human and technological resources to filter uploaded content when it serves its business purposes."