A Japanese whale research group filed a lawsuit with a U.S. federal court Thursday against Sea Shepherd Conservation Society and founder Paul Watson, demanding they be ordered to cease disrupting its whaling activities. The Institute of Cetacean Research and another plaintiff, Kyodo Senpaku Kaisha Ltd., are seeking a court order to prevent Sea Shepherd and Watson from "engaging in activities at sea that could cause injuries to the crews and damage to the vessels," the research group said in a statement. Japan's whaling missions, conducted by the institute as part of what it calls research whaling, have often been obstructed...