In early December, Juliet Weybret, a high school sophomore and aspiring rock star from Lodi, Calif., recorded a video of herself playing the piano and singing “Winter Wonderland,” and she posted it on YouTube.
Juliet Weybret on YouTube, protesting the site’s removal of her music video.
A teacher of sign language used music by Foreigner as background, so his video was removed.
Weeks later, she received an e-mail message from YouTube: her video was being removed “as a result of a third-party notification by the Warner Music Group,” which owns the copyright to the Christmas carol.
Hers is not an isolated case. Countless other amateurs have been ensnared in a dispute between Warner Music and YouTube, which is owned by Google. The conflict centers on how much Warner should be paid for the use of its copyrighted works — its music videos — but has grown to include other material produced by amateurs that may also run afoul of copyright law.
“Thousands of videos disappeared,” said Fred von Lohmann, staff lawyer for the Electronic Frontier Foundation, an Internet civil liberties group that asked affected YouTube users to contact it. “Either they turned off the audio, or they pulled the video.”
A spokesman for Warner Music said that YouTube’s system for identifying copyrighted material does not distinguish between professionally made music videos and amateur material that may include copyrighted works.
“We and our artists share the user community’s frustration when content is unavailable. YouTube generates revenues from content posted by fans, which typically requires licenses from rights holders. Under the current process, we make YouTube aware of WMG content. Their content ID tool then takes down all unlicensed tracks, regardless of how they are used,” said Will Tanous, a spokesman for Warner Music.
In addition to Ms. Weybret’s video, family home videos that included a portion of a song playing in the background have been removed, as have any number of videos that use music in goofy ways, from montages to mash-ups.
When a man posted a video of himself using music to teach sign language, the audio was switched off because he lacked the proper copyright clearance to use Foreigner’s 1980s song “Waiting for a Girl Like You.”
More broadly, however, the takedown notices are a glaring example of the rising tensions between Internet sites that distribute content free and owners of copyrighted material.
In late December, Warner and YouTube failed to agree to terms on a new licensing deal that would have paid Warner a cut of advertising revenue in exchange for permission to stream the music company’s videos. Warner then began having its music videos removed from YouTube. The site has licensing deals with the other major music companies, and had a deal with Warner for two years before the recent impasse.
The situation with Warner has created a double-barreled risk for YouTube. Professionally produced music videos are some of its most-watched material — six of the top 10 most popular videos of all time are music videos, and the most-watched video ever on YouTube is not a bulldog on a skateboard, but an Avril Lavigne video, with more than 117 million views. (The skateboarding bulldog, by contrast, has almost 6.8 million views.)
YouTube more recently began blocking music videos from all companies from its site in Britain after failing to reach terms with PRS for Music, a group that collects royalties on behalf of singers and songwriters.
Keeping a steady supply of music videos on its site is important to YouTube’s effort to increase the flow of advertising dollars. At the same time, the site’s cachet relies on being a place where users like Ms. Weybret can freely display their own material. Google does not disclose advertising revenue for YouTube, and estimates among analysts range widely, from $200 million to $500 million a year.
Ms. Weybret says she has been hesitant lately to use YouTube as an outlet for her musical talents. “I’m kind of nervous now about putting up covers,” said Ms. Weybret, 15, who plays in a band with her friends called the Knockouts.
The question for the two sides is, who will users blame — YouTube or the record label, in this case Warner?
“I feel like the public’s perception of the record labels is so hostile that YouTube will be able to deflect any complaints,” said Phil Leigh, a new media analyst who runs Inside Digital Media, a consulting firm.
Chris Dale, a spokesman for YouTube, said, “While we work with music labels to keep music on the site, sometimes our negotiations don’t pan out, and we understand that this can be a big disappointment to our community.”
Mr. Dale said that YouTube offers users the chance to dispute a copyright claim, or use a feature of the site to swap in a new track to replace the offending song.
