Another big thing with china is that they consider all maps and satellite pics to be state secrets that require strict approval before being published. If you ever look on google maps, the satellite pics dont match up up the maps pics. Most are off by at least 100 ft and that is because all the map data china releases has the coordinates randomly changed by a random amount in a random direction and it is different for every city. Baidu maps does not have this problem because they actual had people sit down and manually correct all the maps to match up with the satellite pics but the gps coordinates are still wrong so when you look on your phone you are rarely ever in the correct position on the map