Afraid if the story plot of THE TWILIGHT SAGA: BREAKING DAWN leaked out, Summit Entertainment makes the system extra security. One way is with not allow anyone to bring this film script out of the set. Robert Pattinson and Kristen Stewart could not prepare themselves with reading their scripts at home.
In the news reported by Splash News is mentioned if this protection has been applied at the audition begins.
This rule was also applied to the two main characters of this movie. Robert Pattinson and Kristen Stewart also never see this movie scripts until shooting began. After shooting finished, all scripts must be returned and no actor who allowed to leave the set until all scripts be returned. This step is taken Summit Entertainment to protect this movie scripts not to leak.