Viewed from a distance, music labels, movie studios and TV networks have all been fighting the same battle ad nauseum against copyright interlopers. And there's never been any question who their lawyers should be calling. Once upon a time, it was Napster. These days, it's YouTube.

But there's something different about this particular fight. Earlier this month, Viacom (VIA) asked YouTube to remove 100,000 unauthorized videos from its site. YouTube complied, but Viacom's not so dense as to think that YouTube hasn't been a boon to its most popular shows. Surely all those Steven Colbert clips formerly on YouTube only encouraged more people to watch Comedy Central every night at 11:30.

The same argument has been made regarding music: All that MP3 swapping ultimately promotes individual songs and their artists, even if it doesn't line anyone's pockets in the near future. But in fact, unauthorized video clips are far less threatening than illegal MP3s. They offer all the promotional advantages with less of the cost to the copyright owners. As James McQuivey, an analyst with Forrester Research, explained to CNET.com:

Video is not like the music space, where access to or a download of a free track will satisfy a person's interest in a particular copyright material and cause the creator to directly lose money, said McQuivey.

While an MP3 provides access to a hit single in its entirety, reducing the likelihood that it will be purchased, a video clip of MTV's Laguna Beach may very well motivate viewers to tune into the commercial broadcast. Someone at Viacom gets this distinction, which is why, in the next few months Viacom will start posting its video clips on its own websites and let blogs link to them.

The corporate lawyers may be playing hardball with YouTube, but deep down the executives must know that YouTube is no Napster.