skipkent writes with news that Britain is planning to use high-tech, non-lethal sonic weapons to provide security at the Olympics this summer. The Ministry of Defense says they intend to use the devices primarily as giant loudspeakers. But if they find themselves in need of a way to disperse crowds, the weapons can project sound up to 150 decibels, causing physical pain within a few hundred meters. "It has been successfully used aboard ships to repel Somali pirates." The maximum range for alarms and warnings is 3km. "Police and military planners say they are preparing for a range of security threats at the Olympics including protesters trying to disrupt events and attacks using hijacked airliners."