I tend to agree with Kevin. The only real copyright on a building has more to do with the blueprints and whether another architect copies protected design elements. If you plant a building out in public, you can't lay claim to every photon that might possibly have bounced off of it. And, after all, all we're really doing is collecting those stray "free" photons.

Philosophically, I think the same about photographing people "in the wild", but civility would have me restrain myself from photographing someone who, directly or indirectly, makes it clear they don't want to be in the picture.