If you draw polygons based on what you see on Google Maps (or any other copyrighted map), your polygons might be found to be a derived work of the original Goog

If you draw polygons based on what you see on Google Maps (or any other copyrighted map), your polygons might be found to be a derived work of the original Google Map. Otherwise, you could just trace all the roads on Google Maps to make your own $BLAH Maps, that's obviously not legal.