There is a difference, in other words, between the fact that this technology exists, and how it is applied. For example, one application is to use this fingerprinting technology to detect and filter.

However, another application is that it could also allow a Web 2.0 user to search for videos/etc. in which a work that he or she likes has been sampled and put to good fair use. That is, if I like a particular video or song, using this technology I can now say “find me all the videos that sample or remix or mashup from this seed video”. That would then allow me to find new and interesting subgenres and communities of practice around videos that were not possible, before.

This is now entirely within the realm of technological possibility. Has been for many years, actually, but folks like Google have been too busy “innovating” to ever bother with this kind of search technology.