Kevin sent me this weapon of choice the other day:
The idea of this project was to create a fully-automated sentry gun, capable of picking out a human target and accurately tracking and shooting him or her in the heart. Really, the idea was to find a cool robotics project for the summer while I was working at an advertising agency, and I’d only ever seen sentry guns in movies (like Congo) and video games (Half-Life 1, Half-Life 2, Team Fortress Classic). I couldn’t find any record of anyone building one, even the military, although it seems likely I just didn’t look hard enough. It’s a pretty simple technology.
I think I can answer why there arn’t any of these systems in the real world. You just can’t trust a robot to not shoot you in the back. Thats a tough one to code around.