Hunnam's casting as Christian Grey has angered die-hard fans of the erotic novel by author E L James.
The 33-year-old's show has already witness the hysteria as the fans have been swarming the TV show's set with the books in hand, said the Hollywood Reporter.
The extra security was hired for Hunnam during the September 7 premiere of 'Anarchy' by Universal studio, who went extra mile for the security of their leading man ahead of movie shooting.
The film directed by Sam Taylor-Johnson will release next year.