James Cameron is known for making epic films but we are sure even he never imagined that one of them could be the highest grossing film of all time. In 2009, Avatar grossed over $2 billion, almost double what he made with his former major motion picture, Titanic. It is said that Cameron is a pretty intense guy. In Titanic, actors claimed that he threatened to fire anyone who needed a bathroom break while filming the "sinking" scenes and often actors would just relieve themselves in the ocean. In Avatar, the rumor was that he would nail actors' phones to the doorway if they rang during filming. Whatever his method, it clearly works! Source: IMDB