The increasing complexity of technology in fields such as robotics has really become astounding. Despite the wondrous creations that people make for productive purposes, there is always going to be the flip side of the coin, where knowledge is used for destructive purposes.
One thing that is particularly worrying is the use of military machines that kill by remote. Although it's no more impersonal than wiping out a city by dropping a bomb from a plane, there's something crazy scary about the idea of autonomous killing machines.
The world has refused to enact Asimov's Three Laws of Robotics. In fact, research in military robotics is a top priority. As a result of humanity's negligence, we have crossed the ethical boundary into mechanized mayhem. I saw this historic story on disinfo.com:
Here is an actual photo from the mission: