WASHINGTON, (AP) -- Environmental and animal rights activists who have turned to arson and explosives are the nation's top domestic terrorism threat, an FBI official told a Senate committee on Wednesday. Groups such as the Animal Liberation Front, the Earth Liberation Front and Stop Huntingdon Animal Cruelty are "way out in front" in terms of damage and number of crimes, said John Lewis, the FBI's deputy assistant director for counterterrorism. "There is nothing else going on in this country over the last several years that is racking up the high number of violent crimes and terrorist actions," Lewis said. ALF...