One of the dangers of the near future may be tiny, insect-sized drones-- much smaller than the "slaughterbots"-- which are essentially programmable bullets which can seek out an individual and kill him.
They can wait until someone opens a door, then go into a building, down halls, into a room and find their target. They would be small enough that no one is likely to notice them until it is too late. Supposedly, at the current time, they would be unstoppable, limited only by their flying time which limits their range.
I suspect their flying time wouldn't be much of a limit if there was a desire to increase their range. I can imagine them hitching a ride on a series of vehicles heading in the direction they want to go, switching vehicles until they are close enough to take off on their own. They could extend their flying time by not flying when they don't need to. There's no hurry.
Yet, a statist of the borderist variety actually claimed that this is a good illustration of why "better border security" is essential.
How would border security protect people from mini killer drones when there's no way to protect people from them anywhere else?
All these drone bullets would need to do is to fly over the "border"; over any fence, wall, or troops-- remember they are all but undetectable and could go as high as necessary-- and, depending on whether the flight time/range issue has been solved or not-- either go directly after their target or hitch a ride deep into the country until they are within range. They wouldn't depend on any vehicles, products, or people crossing the border at all.
When your brain is infected by the statism virus, it's difficult to think straight. A few do; most don't.
To me, this just shows that people need to have the freedom to experiment and find dangerously innovative ways to fight back and defend life, liberty, and property from all violators. If your drone is over my property, it's fair game. That you have a badge or a government "job" changes nothing.