The maps on Google and Bing are mostly, if not all, copyrighted images. Suppose I use the "Earth" view and zoom in on a building. If I were to draw an outline of that building (with the help of the map), would the drawing I made be infringing on the copyright of the map?
The copyright owner of a work has the exclusive right to "reproduce the copyrighted work" or to make "derivative works" of it. 17 USC 106.
Copyright law is older than the photocopier, and it applies to copies made by means of any technology. If your intent is to duplicate the protected work, whether you do it by tracing, photocopying, or even freehand, you are infringing that right.
It is possible that you could squeeze into one of the copyright exceptions, such as fair use, but these are much narrower than people tend to assume they are (especially outside of the U.S.), and they boil down to: "Well, yes, I copied your copyrighted work, but..."
The bottom line is: is it copyrighted? Did you copy it, in whole or in part? Then, unless you have a very good reason, you've infringed the copyright. Whether you do it by means of tracing paper, jellygraph, or iPhone doesn't matter.