The date, Nov. 5, is significant for its dramatic placement in the film and comic book “V for Vendetta,” about a freedom-loving terrorist who destroys an authoritarian government that’s come to power in the U.K. “Remember, remember the 5th of November,” is his saying, hearkening back to the “Gunpowder plot” of 1604, in which the terrorist Guy Fawkes was captured and executed for his attempt to blow up Parliament.