And some little kid just happens to wonder on the place, oh well what difference does some dead kid mean.
How does he get shot? It is internet controlled, right? Why is he trespassing on private land?
The hogs are more dangerous to kids than this set up.
I didn't get the feeling it was automagically controlled, like with motion detectors, as in if any motion is detected, the shotguns start shooting. I think it's just cameras that feed back to a control location where a human decides to fire the weapons or not. So it should be pretty safe IF EVERYTHING WORKS AS INTENDED. You'll be sorry you built a thing like that if some hacker takes over control of it from his mom's basement or it gets some bogus signals online and erroneously thinks you're ordering it to fire.
That having been said, the guy is obviously a smart guy and may very well have multiple failsafes to prevent those issues, but it would be interesting to see what he had.