Human barricade to prevent Olympic missiles installation

PressTV - Human barricade to prevent Olympic missiles installation

Obviously, it is better to have a clear line of fire for a missile to hit, presumably a plane or helicopter and so putting missile sites on top of multi storey flats is a good tactical decision. However, as these things travel rather fast, what difference does 200 feet or so make?  They could be deployed in a park or a football ground, instead of creating a target for terrorists to blow up the block of flats, with the missiles on top of it!