WSJ writes about the impact on the music industry:
The music industry is grappling again with how to protect its copyrights on the Internet, as amateur videos featuring commercial songs flood the Web.
Some of the most popular videos on sites such as YouTube and Google Video show amateurs lip synching to music by the Backstreet Boys, *Nsync and other pop artists. Many home-videos posted on such sites include songs as soundtracks, as well as snippets of concerts captured by music fans with their cellphone cameras. Virtually all this material is put online without securing permission from the owner of the rights.
The concerns have taken root as the popularity of video sites — which allow users to post their own and view others’ videos — has exploded, thanks in part to the spread of high-speed Internet connections and the rapidly expanding amount of amateur and commercial content online.