Probably you don't understand where the line is because no one else is quite sure either. Most of the underlying information on Google Maps is public domain—ro

Probably you don't understand where the line is because no one else is quite sure either. Most of the underlying information on Google Maps is public domain—road locations and physical features of the terrain are all uncopyrightable facts. What they claim copyright to are the map visuals: the particular style of drawing the maps, and the photographs they took. (though perhaps even that is debatable, since the photography is a robotic process) You should be able to take the Google data and extract everything uncopyrightable from it to draw your own maps. (And if you're interested in public maps, you should see the OpenStreetMap project.) But say you want to include some of the other things on Google Maps--place markers for hotels and restaurants, for example. Any one of them is an uncopyrightable fact: that's where it is. But what if you choose to mark the same collection of the same sorts of things that Google has marked--are you infringing on their copyright in the selection? The more you can make an argument that there was some original thought in the selection the harder it is to tell. US law is pretty clear on plain facts being ineligible for copyright, even if it took work ("sweat of the brow") to compile them. But copyright in things like collections of data is much less clear.