Back in 2009, Capitol and other record labels sued Vimeo over "lip dubs," or videos featuring people lip synching to famous songs. The labels argued that the clips infringed copyright. The case stalled for a few years, but litigation is now heating up again in federal court in New York, Hollywood Reporter recently reported. Vimeo, now owned by IAC/Interactive, is arguing that the lawsuit should be dismissed on the theory that it's protected by the Digital Millennium Copyright Act's safe harbors. Those provisions broadly say that Web platforms aren't liable for copyright infringement by users, providing the sites take down infringing content upon request. But those safe harbors have some big exceptions, including one for companies that know about infringing clips on the site. The labels say Vimeo isn't eligible for the safe harbors. They contend in legal papers filed last week that Vimeo knows of infringing clips on its service, "refuses to remove them," and "induces" users to infringe copyright. At this point, the companies haven't yet addressed what's probably the most interesting issue -- whether the lip dubs are a fair use. That could go either way, but it seems like Vimeo is in a stronger position now than three years ago -- thanks to, of all companies, Righthaven. How could the Web's most notorious copyright troll have helped Vimeo? The answer turns on the factors that go into fair use. One involves how much of the original work is used by an alleged infringer. Lip dub clips often show people lip synching a song in its entirety. In the past, many observers assumed that using 100% of a work -- as opposed to short excerpts -- would weigh heavily against fair use. But in 2011, a judge in Las Vegas ruled in a lawsuit brought by Righthaven that a blogger who reposted an entire article from the Las Vegas Review-Journal made fair use of the piece -- a 1,000-word article about immigrants who were deported after being arrested for misdemeanors. Of course, that ruling isn't the last word on fair use. But it certainly won't hurt Vimeo, if the company intends to argue that lip dubs don't infringe copyright. Judges deciding fair use issues also look at the nature of the original work, whether the use affects the market value of the original, and whether the new use "transforms" the original. Vimeo seems to have a very strong argument that the lip dubs are transformative. The company also might have a good case that lip dubs don't cut into the market for the originals -- though without some empirical data, it's hard to say whether that's true. Still, it's worth asking whether the lip dubs don't help the record labels by spurring people's interest in music. Surely it's not a stretch to think that some Vimeo users have gone on to become fans -- and paying customers -- of musicians they discovered through the site.