A federal judge temporarily banned the use of mid-frequency active sonar by the Navy. This restraining order comes three days after the Navy acquired an exemption from the ever-lovable Defense Department to use the sonar, despite the fact that it violates the Marine Mammal Protection Act. The new ruling was made possible by the Natural Resources Defense Council, an environmental group, who had sued the Navy for planning to use the sonar this Thursday off the coast of Hawaii. Florence-Marie Cooper, the District Judge in this case, wrote in her order that the plaintiffs “have shown a possibility that RIMPAC 2006 will kill, injure, and disturb many marine species, including marine mammals, in waters surrounding the Hawaiian Islands.” The Navy could have decided to conduct its experiments in less densely populated waters, but it simply chose not to. The restraining order will remain in effect until July 18th when a hearing will be held to determine further action.