Security issues, I think. Russia is very centralised, and many, many things of strategic importance are in the city. Many areas around it (near state residences

Security issues, I think. Russia is very centralised, and many, many things of strategic importance are in the city. Many areas around it (near state residences, army bases, etc.) are also no-flight zones: https://img-fotki.yandex.ru/get/5902/214603206.b7/0_139f47_d07ba970_XXL.jpg https://img-fotki.yandex.ru/get/5902/214603206.b7/0_139f47_d... Some source state that it is possible to fly over Moscow in certain corridors, but only on the altitude of at least 8100m.