I find this OSM diary entry and comment thread about map and geocoded photo copyrights interesting. This brings me to the particular situation of primary-source publicity maps, i.e., maps of places made by the people who own/manage the place.
Let's say you were surveying on the ground a large public zoo, and you happen to come across a "you are here" map somewhere there. Is is wrong to get your bearings by looking at the map or even comparing the map with your own to find out areas you have missed? While it's copyright infringement to take a photo of the map and distribute it (since the artistic and creative elements of that map is definitely under copyright), using the map as a source of facts, not creative expression should be ok.
Isn't looking at that "you are here" map which was created by the zoo owners for publicity purposes a form of on-the-ground surveying? Aren't street signs a textual form of "you are here" as well? Take note that we are all going into a really fuzzy gray area here.
For an even more fuzzier example, take the case of Japan addresses (see this Wikipedia article). In most dense urban areas of Japan, most highway=unclassified/residential roads are unnamed and places are addressed by using a building-number (gō), then block-number (banchi), then area-number (chōme) system. You can often find maps of the buildings per block so that you can locate a particular building in a particular block. These maps function in the same way as street signs do in Western countries. I've been to Tokyo and I've used these maps to locate buildings.
So, is it so wrong to use those building maps as a source of facts and information, especially when you're surveying them on-the-ground, the same way you use street signs to collect street names and access restrictions?