Open street map's license allows anyone to use their data, but if you "build upon" their data then you must release your version with the same license. Google m

Open street map's license allows anyone to use their data, but if you "build upon" their data then you must release your version with the same license. Google maps would not be able to incorporate OSM's licensed data to their own data without releasing their own proprietary data freely as well, which they aren't willing to do.