Gregory Maxwell writes:

Another point about attribution which we need to be mindful of is the proposed Orphan Works law in the US which is getting closer and closer to passing: http://www.govtrack.us/congress/billtext.xpd? bill=s110-2913

I expect it to make attentive copyright holders far more aggressive. We can expect to get perfunctory complaints about many of our valid fair use images just as we already receive from trademark holders.

I would be surprised if the Orphan Works Act led to copyright holders' being more aggressive, especially since the institutional copyright industry is already hyper-aggressive. (They oppose the Orphan Works Act.) The thrust of the Act is to address cases in which copyright holders are difficult or impossible to determine. Aggressive copyright holders almost by definition fail to fall into that class.

--Mike