The Programmed People by Jack Sharkey

Lloyd didn't like Goons. He knew he was supposed to recognize in them the ultimate in police efficiency, but they still gave him chills. A Goon, a Governmental Opposer of Neutrality, was a fearful sight. All were of a size, equal to a micrometer-breadth, a monstrous eight feet of thick metal and ponderous wheels, bathed from base to apex in the blurry grey pulsations of their protective force-fields, through which no power on Earth could penetrate. The metal arms were multi-jointed and dextrous to a fantastic degree, despite the clumsy look of the thick tripodal fingers at the ends of the arms. The "eyes" were wide-set telelenses, a pair of them, to report back all they saw to the Brain itself, deep beneath the teeming streets of the Hive. And each Goon spoke with the cold, inflectionless tones of the Brain, the flatly indifferent voice that could only emanate from a mind of glowing vacuum tubes and magnetic fields. From any or all of a Goon's six fingertips could spring the dreaded Snapper Beam, an electronic refinement of vibrations that struck the human nervous system almost identically with the chemical effect of strychnine poisoning, except that a Snapper Beam worked instantly, and always fatally. A brush of the invisible force, and a man's face creased into the frenzied grin of a madman, his legs danced wildly, uncontrollably, and the muscles of his back contracted tightly, relentlessly, remorselessly, until his spine cracked in two.

Lloyd had never seen it employed, save in the theatres. Dispersal of insurrection by Goons was a popular theme in films. A mob could be efficiently halted by a sweeping Snapper Beam, to fall like broken puppets. Goons never lost a film battle. Or a real one.