It's harder than you think
Google has responded in the debate about video fingerprinting as a way of controlling the use of copyrighted content on YouTube. Both Microsoft's Soapbox and MySpace video already have video fingerprinting in place, so you can understand many content owner's frustration about the delay.
However, Google does make some interesting points about the difficulties in identifying copyrighted content when sometimes copyrighted content may be legitimately posted independent of Google's content deals. As it says, porn or violence are reasonably clear to all (but still a judgement call) whereas users may not know if a piece of copyrighted content is legal or not.
Whatever the merits of the arguments, Google needs to implement their technology sooner rather than later to appease the concerns of many content owners.