In the terms established by the usage of Google:
3.2.1 General Restrictions. Customer will not: (a) copy, modify, create a derivative work of, reverse engineer, decompile, translate, disassemble, or otherwise attempt to extract any or all of the source code (except to the extent such restriction is expressly prohibited by applicable law)
And regarding maps under the paragraph of Prohibited Conduct:
Copy the content (unless you are otherwise permitted to do so by the Using Google Maps, Google Earth, and Street View permissions page or applicable intellectual property law, including "fair use").
What determines then the limits of 'fair use'?
Is it possible to make a whole world map inspired by the photographics provided by google maps without actually using them by taking them?