Dig into the recesses of your memory and recall what your mother told you about running with scissors.
She told you not to, right? Because you might stumble and fall and the pointy end of the shears may end up impaling you. Which, can be bloody and inconvenient and not something you need when all you wanted to do was cut out a coupon on a box of Healthy Choice pudding so you can redeem it for a curious amount of frequent flyer miles.
Apply this lesson to a brainwashed jihadist with a bomb strapped to his chest riding one of those newfangled, faulty “hoverboards” (that aren’t actually hoverboards, just motorized, funny-looking skateboards) down the street.
In this case, the bomb is the scissors and the running is the riding the moving platform.