“Picture a typical playground. It’s a sunny day and kids are playing tag, smacking tetherballs around and hanging off the monkey bars. Now imagine this: There’s not a single parent or adult in sight, but a 3-foot, 260-pound robot on patrol instead.

Take a closer look and you’ll see the children wearing small electronic devices, tiny radio transmitters that signal the bot when the kids wander out of safe range. Equipped with a camera, the robot relays live video to a remote security facility. When a stranger approaches one of the children, the robot, controlled remotely, gets aggressive. On six wheels, it pursues the intruder, flashing bright lights and sirens and spewing a thick cloud of smoke. The cyber-guard snaps a few pictures, too.”