Surprising new products pop up all the time at high-tech trade shows. But at the Consumer Electronics Show in Las Vegas last month, one was particularly shocking. Volunteers by the dozen lined up at the Taser International booth for a chance to get blasted with 50,000 volts from the company's newest stun gun. "It felt like I got hit by lightning 100 times," said Jeremy Friedbaum, 46, of Provo, Utah.
The new stun gun, the Advanced Taser M-18L, looks like a pistol. But instead of firing bullets, it shoots tethered darts that hook into the skin or clothes. Victims typically scream...