Rapper 50 Cent is suing Taco Bell for $4 million over a guerrilla ad campaign, reports E! Online. The fast food giant wrote Fiddy, suggesting he change his name to 79, 89, or 99 Cent for a price promotion. By releasing the letter to the media, he claims Taco Bell unfairly traded on his brand, "diluting the value of his good name." (More 50 Cent stories.)