Weapons that deliver an electrical current through muscle to cause pain and/or to interfere with operation of the muscle; hand-held weapons having terminals for coupling an electrical current through muscle proximate to the terminals to cause pain and/or to interfere with operation of the muscle; weapons that launch probes to muscle to conduct an electrical current from the weapon through the probes to cause pain and/or to interfere with operation of the muscle; cartridges for use with any of the aforementioned weapons