Google is using digital and analog fingerprinting technology for both audio and video contents. Audio is easier, but video is doable as well. It's a large work, but Google wants to do it anyways, they are digitizing every single movie, tv show, even every single second of every single TV channel ever broadcast. They gather all DVDs released, even capture from VHS and stuff like that. Eventually, Google could release ALL OF IT onto Youtube and Google TV, provided that Google sorts out the copyright laws or copyright licencing systems. Youtube would like all copyright holders to want to allow display of all these videos and simply monetize the views with overlay ads. Youtube is working hard to show to copyright holders that they gain more from allowing unlimited use on Youtube of their contents, even to officially release all the movies, tv shows and more onto Youtube and just monetize it. Colbert and John Stewart wouldn't be so popular today if it wasn't for Youtube making them extremely popular in 2006-2007 and Viacom has been loosing out on possibly hundreds of millions of dollars in overlay advertising these past 3 years by not allowing Youtube to feature all of the episodes and clips from these shows.