Since it was enacted in 1970, federal prosecutors have used the Racketeer Influenced Corrupt Organizations (RICO) law for its original purpose: dismantling mob syndicates. Over the years, though, the law has become a weapon in commercial litigation, as well. On Monday, April 20, the influential U.S. Court of Appeals for the Second Circuit in New York will hear arguments on whether companies may use RICO to go after plaintiffs' attorneys whose lawsuits allegedly evolve into extortion schemes. How the New York court rules in a case involving Chevron and oil pollution in Ecuador could redefine the terms of mass litigation over such ills as pollution, workplace hazards, and job discrimination.