The Portal Denial System is basically a system of lightning guns that can be used to guard a door, as you’ll see in the demonstration. Unfortunately, it’s only authorized for sale to the US government. Video after the jump.
The discharges can be tuned to be lethal or “less lethal,” and can disable vehicles by frying their electronics. Although it looks like lightning (and it pretty much is), the heart of the system is actually a laser. The laser fires femtosecond pulses, which create a superconductive plasma channel to the target, focusing the electrical discharge