Great clip from a highly underrated movie
(from the same director as "Starship Troopers").

Yeah, the idea of autonomous weapons is scary (I can only think of Saberhagen's Berserkers) but when you think about it, many weapons are, to a certain extent, autonomous. Think of fire-and-forget homing missiles, Phalanx point defense guns, and even the humble mine. They are all designed to kill after making a decision unassisted by humans.

I once worked on the preliminary pattern recognition research for an autonomous homing torpedo (nothing came of it). It was purely a recon platform, but it would not take too much modification to put a warhead instead of a camera on it.