[OSM-newbies] Where is the line between "facts" and "creative works"?

[David Carmean]

OK, say I go wandering some recreational trails with my GPS.  Some of them are 
well-marked, at the trailheads and along the way.  Others are not so well-marked, but 
are nonetheless official trails with names, etc.  For the latter, info is available 
in published maps and local government-produced GIS data.

How do we obtain the trail names and other data?  Why is copying the name of the 
trail from the physical sign different than copying the name from a map depiction?  
>From the GIS shapefile?

Same question applies if I trace the trails using public domain aerial imagery 
(I'm fortunate to live in a coverage area for USGS Urban orthophotos).  

Thanks.