Okay so I read a story a long time ago in an aviation magazine. The concept was every pilot should have a golden gun with one bullet. This bullet would never miss it's target but you only ever get one and you can use it no questions asked as long as you're in the air.

The theory was that this is like flying; if you see a pilot doing something that's going to get someone killed you should be allowed to kill them first. And every pilot will always wonder if some other pilot can see them and think twice about being stupid because it might get them killed.

I think about this a lot.