But the stormtroopers might as well be robots, or pieces of scenery, so to kill them carries no charge of murder. It's not so much that the emotional impact is blunted as that it falls only on one side.

I guess Lucas tries to rationalise it by making them clones in Episode II. It provides for a creepy bit in Episode III, but I'm still not sure it was worth it.

I still need to see Brazil . . .

I think it's a brilliant movie, although there is a lot of contention on the subject.