Researchers working for the US military are developing a laser stun gun capable of inflicting paralysis and excruciating pain on anyone unlucky enough to be within its 2 km range. The new weapon, known as a PEP or Pulsed Energy Projectile, is being touted as a crowd-control measure to 'neutralise' rioters, and could be in action by 2007. It emits a powerful laser beam which generates a charged plasma cloud whenever it hits someone. The expanding plasma over-excites the nervous system triggering severe pain sensations, and temporary paralysis. At the moment the researchers are working on ways to optimise the system so that it's even more effective at producing pain but without damaging healthy tissue. However, some pain experts around the world are horrified and have expressed concerns over the long-term effects of such a weapon which could include life-long pain syndromes triggered by the stun gun causing the nervous system to re-wire itself.