sentences:  Their campaigns are nonviolent and many times involve one or more of the five Greenpeace ships which first made the organization famous in the 1970s.In late December 2005, Japanese whaling fleets experienced heavy opposition from Greenpeace, who protested that the Japanese were continuing their commercial whaling under the guise of research, and even worse, they were doing so in the Southern Ocean Whale Sanctuary.They sent volunteer workers in inflatable boats to get in the line of fire in order to stop the whaling.