Hedge fund mogul William Ackman, who has spent more than two years accusing Herbalife Ltd (HLF.N) of running a pyramid scheme, said on Monday that shutting down the company is “one of the most important things” he can do. Speaking at a meeting of the Council of Institutional Investors’ in Washington, Ackman said again that Herbalife has caused “enormous harm to a very vulnerable population” by targeting undocumented Latinos in the United States and other poor people.