Trent Reznor explained earlier this week on the Nine Inch Nails blog how "safe harbor" under the DMCA is restricting them from launching a site where fans can upload their own mixes of Nine Inch Nails songs as Universal, owner of their master recordings, is afraid they may sponsor the same technical violation of copyright that they are suing Youtube and Myspace for. This is because the remixes may contain uncleared material, that Universal does not own, such as a mashup, sample or whatever.
This is a very interesting double-edged sword in regards to the DMCA. As during the early MP3.com days we had people sitting in a room listening to every track that was uploaded for copyright material, cover songs, etc. These days most companies rely on DMCA safe harbor to be re-active rather then pro-active at taking down content. It is really a shame that mashups and sampling are seen as such a liability. Rather than seeing it as a sign of appreciation and respect, we turn around and would sue the creator for a small piece of the action. I can see it to a certain degree, but clearing rights needs to be much much easier then it is now if we truly expect people to clear rights for things like a sample or mashup.