I don't know how they do it, but they do it, I'm certain of it.
Nearly every science fiction movie of the last couple of years had a phrase in which extraterrestrial life is ridiculised or depicted as hostile. These phrases must have been inserted into the dialogues, because they clearly fall out of tone with the rest of the play. 'Solaris' had it ("who are you with, them or us?", and that was totally off - as if Solaris was hostile), 'the Matrix reloaded' had it (equalling extraterrestrials with vampires and werewolves - hello-o), 'Signs' obviously wanted to scare us for crop circles (ask yourselves why - and
listen to what experts say about this).
Count the number of movies that charismatize the CIA since the last three years and tell me that's a coincidence. Look at the rise of historic, patriotic and military movies and tell me that's a coincidence. Hollywood is the ultimate global propaganda/brainwash tool. Irresistable for bending public opinion. Think about it.