Unmanned, remotely-controlled robotics have become a multi-billion dollar industry, thanks in large part to one customer — the US government. That's due to a shift in strategy over the last decade as the US has begun deploying more unmanned systems every year, with a current force of 7,000 drones and 12,000 ground robots in use. Al-Jazeera's video series "Fault Lines" took an in-depth look at the amazing technology behind these robots as well as the legal and political implications of these tools — be sure to keep your eyes peeled for an interview and demonstration by Dennis Hong, who we profiled back in November. This video is a must-watch for anyone interested in robotics and the history of their role in modern warfare.