i think Cameron can't even sue them, because this is a movie about a ship named "Titanic II" , hence the title. Technically it's not the sequel to the movie "Titanic" 
“It appeared that there had even been demonstrations to thank Big Brother for raising the chocolate ration to twenty grams a week. And only yesterday, he reflected, it had been announced that the ration was to be reduced to twenty grams a week. Was it possible that they could swallow that, after only twenty-four hours? Yes, they swallowed it.”
- George Orwell, ‘1984’







