In their quest for less bloody approaches to crowd control, the American defense contractor Raytheon unveils "Silent Guardian", a gizmo that broadcasts a beam of pure pain up to a quarter mile (in the form of microwaves tuned to resonate with the pain receptors in your skin), with no lasting physical effects. Hardened Marines can't take it for more than a second --- they involuntarily turn tail and run. As would anyone else, if they can. If they can't, well, quoth the reporter...
[These weapons] are quick, clean, cheap, easy to use and, most importantly, leave no marks. What would happen if they fell into the hands of unscrupulous nations where torture is not unknown?